Glossary
The harder words used in Codexery entries, in one place. Every definition is the opening sentence of the linked source article, quoted as written, so a word means the same thing on every page. 774 terms · updated 30 September 2026.
A
- Acetylcholine
- Acetylcholine (ACh) is an organic compound that functions in the brain and body of many types of animals (including humans) as a neurotransmitter. Definition: first sentence of Wikipedia: Acetylcholine (CC BY-SA 4.0)
- Acid phosphatase
- Acid phosphatase (EC 3.1.3.2, systematic name phosphate-monoester phosphohydrolase (acid optimum)) is an enzyme that frees attached phosphoryl groups from other molecules during digestion. Definition: first sentence of Wikipedia: Acid phosphatase (CC BY-SA 4.0)
- Acid rain
- Acid rain is rain or any other form of precipitation that is unusually acidic, meaning that it has elevated levels of hydrogen ions (low pH). Definition: first sentence of Wikipedia: Acid rain (CC BY-SA 4.0)
- Actin
- Actin is a family of globular multi-functional proteins that form microfilaments in the cytoskeleton, and the thin filaments in muscle fibrils. Definition: first sentence of Wikipedia: Actin (CC BY-SA 4.0)
- Action potential
- An action potential (also known as a nerve impulse or "spike" when in a neuron) is a series of quick changes in voltage across a cell membrane. Also: action potentials. Definition: first sentence of Wikipedia: Action potential (CC BY-SA 4.0)
- Activation energy
- In the Arrhenius model of reaction rates, activation energy is the minimum amount of energy that must be available to reactants for a chemical reaction to occur. Also: active. Definition: first sentence of Wikipedia: Activation energy (CC BY-SA 4.0)
- Active site
- In biology and biochemistry, the active site is the region of an enzyme where substrate molecules bind and undergo a chemical reaction. Definition: first sentence of Wikipedia: Active site (CC BY-SA 4.0)
- Acute (medicine)
- In medicine, describing a disease as acute denotes that it is of recent onset; it occasionally denotes a short duration. Also: acute. Definition: first sentence of Wikipedia: Acute (medicine) (CC BY-SA 4.0)
- Adaptive immune system
- The adaptive immune system (AIS), also known as the acquired immune system or specific immune system, is a subsystem of the immune system that is composed of specialized cells, organs, and processes that eliminate pathogens specifically. Also: adaptive immunity. Definition: first sentence of Wikipedia: Adaptive immune system (CC BY-SA 4.0)
- Adenine
- Adenine (symbol A, or Ade) is a purine nucleotide base that is found in DNA, RNA, and ATP. Definition: first sentence of Wikipedia: Adenine (CC BY-SA 4.0)
- Adrenal cortex
- The adrenal cortex is the outer region and also the largest part of the adrenal gland. Definition: first sentence of Wikipedia: Adrenal cortex (CC BY-SA 4.0)
- Adrenaline
- Adrenaline, also known as epinephrine and alternatively spelled adrenalin, is a hormone and medication which is involved in regulating visceral functions (e.g., respiration). Also: epinephrine. Definition: first sentence of Wikipedia: Adrenaline (CC BY-SA 4.0)
- Agonist
- An agonist is a chemical that activates a receptor to produce a biological response. Definition: first sentence of Wikipedia: Agonist (CC BY-SA 4.0)
- Alanine
- Alanine (symbol Ala or A), or α-alanine, is an α-amino acid that is used in the biosynthesis of proteins. Definition: first sentence of Wikipedia: Alanine (CC BY-SA 4.0)
- Alarm signal
- In animal communication, an alarm signal is an antipredator adaptation in the form of signals emitted by social animals in response to danger. Also: alarm. Definition: first sentence of Wikipedia: Alarm signal (CC BY-SA 4.0)
- Alcohol (chemistry)
- In chemistry, an alcohol is a type of organic compound that carries at least one hydroxyl functional group bound to a saturated carbon atom. Also: alcohol. Definition: first sentence of Wikipedia: Alcohol (chemistry) (CC BY-SA 4.0)
- Algae
- Algae are any of a large and diverse group of photosynthetic organisms. Definition: first sentence of Wikipedia: Algae (CC BY-SA 4.0)
- Aliphatic compound
- Aliphatic compounds are chemical compounds containing the element carbon that are not aromatic compounds. Also: aliphatic. Definition: first sentence of Wikipedia: Aliphatic compound (CC BY-SA 4.0)
- Allele
- An allele is a variant of the sequence of nucleotides at a particular location, or locus, on a DNA molecule. Also: alleles. Definition: first sentence of Wikipedia: Allele (CC BY-SA 4.0)
- Alloenzyme
- Alloenzymes (or also called allozymes) are variant forms of an enzyme which differ structurally but not functionally from other allozymes coded for by different alleles at the same locus. Also: allozyme, allozymes. Definition: first sentence of Wikipedia: Alloenzyme (CC BY-SA 4.0)
- Alternative splicing
- Alternative splicing, alternative RNA splicing, or differential splicing is an alternative splicing process during gene expression that allows a single gene to produce different splice variants. Definition: first sentence of Wikipedia: Alternative splicing (CC BY-SA 4.0)
- Alveolar macrophage
- An alveolar macrophage, pulmonary macrophage, (or dust cell, or dust eater) is a type of macrophage, a professional phagocyte, found in the airways and at the level of the alveoli in the lungs, but separated from their walls. Also: alveolar macrophages. Definition: first sentence of Wikipedia: Alveolar macrophage (CC BY-SA 4.0)
- Amino acid
- Amino acids are organic compounds that contain both amino and carboxylic acid functional groups. Also: amino acids. Definition: first sentence of Wikipedia: Amino acid (CC BY-SA 4.0)
- Ammonium
- Ammonium is a modified form of ammonia that has an extra hydrogen atom. Definition: first sentence of Wikipedia: Ammonium (CC BY-SA 4.0)
- Amniote
- Amniotes are tetrapod vertebrate animals belonging to the clade Amniota, a large group that comprises the vast majority of living terrestrial and semiaquatic vertebrates. Also: amniotes. Definition: first sentence of Wikipedia: Amniote (CC BY-SA 4.0)
- Amoeba
- An amoeba or ameba (: amoebas or amebas (less commonly, amoebae or amebae)), often called an amoeboid, is a type of cell or unicellular organism with the ability to alter its shape, primarily by extending and retracting pseudopods. Also: amoebae. Definition: first sentence of Wikipedia: Amoeba (CC BY-SA 4.0)
- Amoeboid movement
- Amoeboid movement is the most typical mode of locomotion in adherent eukaryotic cells. Definition: first sentence of Wikipedia: Amoeboid movement (CC BY-SA 4.0)
- Amphiphile
- In chemistry, an amphiphile, also referred to as an amphipath, is a dipolar chemical compound possessing both hydrophilic (water-loving, polar) and lipophilic (fat-loving, nonpolar) properties within the same molecule. Also: amphiphilic. Definition: first sentence of Wikipedia: Amphiphile (CC BY-SA 4.0)
- Ampullae of Lorenzini
- Ampullae of Lorenzini are electroreceptors, sense organs able to detect electric fields. Definition: first sentence of Wikipedia: Ampullae of Lorenzini (CC BY-SA 4.0)
- Amyloid
- Amyloids are aggregates of proteins characterised by a fibrillar morphology of typically 7–13 nm in diameter, a β-sheet secondary structure (known as cross-β) and ability to be stained by particular dyes, such as Congo red. Definition: first sentence of Wikipedia: Amyloid (CC BY-SA 4.0)
- Analogy
- Analogy is a comparison or correspondence between two things (or two groups of things) because of a third element that they are considered to share. Definition: first sentence of Wikipedia: Analogy (CC BY-SA 4.0)
- Anamniotes
- The anamniotes are an informal group of vertebrates comprising all fish and amphibians, which lay their eggs in aquatic environments. Definition: first sentence of Wikipedia: Anamniotes (CC BY-SA 4.0)
- Androgen
- An androgen (from Greek andr-, the stem of the word meaning) is any natural or synthetic steroid hormone that regulates the development and maintenance of male physiological characteristics in vertebrates by binding to androgen receptors. Also: androgens. Definition: first sentence of Wikipedia: Androgen (CC BY-SA 4.0)
- Androstane
- Androstane is a C19 steroidal hydrocarbon with a gonane core. Definition: first sentence of Wikipedia: Androstane (CC BY-SA 4.0)
- Angiogenesis
- Angiogenesis is the physiological process through which new blood vessels form from pre-existing vessels, formed in the earlier stage of vasculogenesis. Definition: first sentence of Wikipedia: Angiogenesis (CC BY-SA 4.0)
- Annular lipid shell
- Annular lipids (also called shell lipids or boundary lipids) are a set of lipids or lipidic molecules which preferentially bind or stick to the surface of membrane proteins in biological cells. Definition: first sentence of Wikipedia: Annular lipid shell (CC BY-SA 4.0)
- Anthropology
- Anthropology is the scientific study of humanity that crosses biology and sociology, concerned with human behavior, human biology, cultures, societies, and linguistics, in both the present and past, including archaic humans. Definition: first sentence of Wikipedia: Anthropology (CC BY-SA 4.0)
- Anti-inflammatory
- Anti-inflammatory refers to any drug, substance or mechanism that reduces inflammation by lessening the redness, swelling, fever, or pain and loss of function which are part of bodies inflammatory response. Definition: first sentence of Wikipedia: Anti-inflammatory (CC BY-SA 4.0)
- Antibiotic
- An antibiotic is a type of antimicrobial substance which is active against bacteria. Also: antibiotics. Definition: first sentence of Wikipedia: Antibiotic (CC BY-SA 4.0)
- Antibody
- An antibody (Ab), or immunoglobulin (Ig), is a large protein belonging to the immunoglobulin superfamily which is used by the immune system to identify and neutralize antigens such as those that exist on bacteria and virus cells, including those that cause disease. Also: antibodies, immunoglobulins. Definition: first sentence of Wikipedia: Antibody (CC BY-SA 4.0)
- Antigen
- In immunology, an antigen (Ag) is a molecule, or portion thereof, that can bind to a specific antibody or T-cell receptor. Also: antigens. Definition: first sentence of Wikipedia: Antigen (CC BY-SA 4.0)
- Antimicrobial peptides
- Antimicrobial peptides (AMPs), also called host defence peptides (HDPs) are part of the innate immune response found among all classes of life. Also: antibacterial peptides. Definition: first sentence of Wikipedia: Antimicrobial peptides (CC BY-SA 4.0)
- Antiparallel (biochemistry)
- In biochemistry, two biopolymers are antiparallel if they run parallel to each other but with opposite directionality (alignments). Also: antiparallel. Definition: first sentence of Wikipedia: Antiparallel (biochemistry) (CC BY-SA 4.0)
- Antisense therapy
- Antisense therapy is a form of treatment that uses antisense oligonucleotides (ASOs) to target messenger RNA (mRNA). Definition: first sentence of Wikipedia: Antisense therapy (CC BY-SA 4.0)
- Apex predator
- An apex predator, also known as a top predator or superpredator, is a predator at the top of a food chain with few natural predators of their own, if any. Definition: first sentence of Wikipedia: Apex predator (CC BY-SA 4.0)
- Apicoplast
- An apicoplast is a derived non-photosynthetic plastid found in most Apicomplexa, including Toxoplasma gondii, and Plasmodium falciparum and other Plasmodium spp. (parasites causing malaria), but not in others such as Cryptosporidium. Also: apicoplasts. Definition: first sentence of Wikipedia: Apicoplast (CC BY-SA 4.0)
- Apolipoprotein
- Apolipoproteins are proteins that bind lipids (oil-soluble substances such as fats, cholesterol and fat soluble vitamins) to form lipoproteins. Definition: first sentence of Wikipedia: Apolipoprotein (CC BY-SA 4.0)
- Archaea
- Traditionally, Archaea included only its prokaryotic members, but has since been found to be paraphyletic, as eukaryotes are known to have evolved from archaea. Definition: first sentence of Wikipedia: Archaea (CC BY-SA 4.0)
- Archaellum
- The archaellum is a unique structure on the cell surface of many archaea that allows for swimming motility. Definition: first sentence of Wikipedia: Archaellum (CC BY-SA 4.0)
- Aromatic sulfonation
- In organic chemistry, aromatic sulfonation is a reaction in which a hydrogen atom on an arene is replaced by a sulfonic acid group. Also: sulfonation. Definition: first sentence of Wikipedia: Aromatic sulfonation (CC BY-SA 4.0)
- Assault rifle
- An assault rifle is a select fire rifle that uses an intermediate-rifle cartridge and a detachable magazine. Definition: first sentence of Wikipedia: Assault rifle (CC BY-SA 4.0)
- Autism
- Autism, also known as autism spectrum disorder (ASD), is a condition characterized by impairment in social communication and interaction, as well as a need or strong preference for predictability and routine, sensory processing differences, focused interests, or repetitive behaviors. Definition: first sentence of Wikipedia: Autism (CC BY-SA 4.0)
- Autoimmunity
- In immunology, autoimmunity is the system of immune responses of an organism against its own healthy cells, tissues and other normal body constituents. Definition: first sentence of Wikipedia: Autoimmunity (CC BY-SA 4.0)
- Automatic firearm
- An automatic firearm or fully automatic firearm (to avoid confusion with semi-automatic firearms) is a self-loading firearm that continuously chambers and fires rounds when the trigger mechanism is actuated. Also: fully automatic. Definition: first sentence of Wikipedia: Automatic firearm (CC BY-SA 4.0)
- Autotroph
- An autotroph is an organism that can convert abiotic sources of energy into stored energy in organic compounds, which can be used by other organisms. Also: autotrophic. Definition: first sentence of Wikipedia: Autotroph (CC BY-SA 4.0)
- Axon terminal
- Axon terminals (also called terminal boutons, synaptic boutons, end-feet, or presynaptic terminals) are distal terminations of the branches of an axon. Definition: first sentence of Wikipedia: Axon terminal (CC BY-SA 4.0)
B
- Bacteria
- Bacteria are ubiquitous, mostly free-living organisms often consisting of one biological cell. Also: bacterial. Definition: first sentence of Wikipedia: Bacteria (CC BY-SA 4.0)
- Bacterial conjugation
- Bacterial conjugation is the transfer of genetic material between bacterial cells by direct cell-to-cell contact or by a bridge-like connection between two cells. Also: conjugation. Definition: first sentence of Wikipedia: Bacterial conjugation (CC BY-SA 4.0)
- Bacterial microcompartment
- Bacterial microcompartments (BMCs) are organelle-like structures found in bacteria. Also: bacterial microcompartments. Definition: first sentence of Wikipedia: Bacterial microcompartment (CC BY-SA 4.0)
- Bacteriocin
- Bacteriocins are proteinaceous or peptidic toxins produced by bacteria to inhibit the growth of similar or closely related bacterial strain(s). Also: bacteriocins. Definition: first sentence of Wikipedia: Bacteriocin (CC BY-SA 4.0)
- Bacteriophage
- A bacteriophage, also known informally as a phage, is a virus that infects and replicates within bacteria. Also: phages. Definition: first sentence of Wikipedia: Bacteriophage (CC BY-SA 4.0)
- Basophil
- Basophils are a type of white blood cell. Also: basophils. Definition: first sentence of Wikipedia: Basophil (CC BY-SA 4.0)
- Basophilic
- Basophilic is a technical term used by pathologists. Definition: first sentence of Wikipedia: Basophilic (CC BY-SA 4.0)
- Benthic zone
- The benthic zone is the ecological region at the lowest level of a body of water, such as a stream, river, lake, or ocean, including the sediment surface and some sub-surface layers. Also: benthic. Definition: first sentence of Wikipedia: Benthic zone (CC BY-SA 4.0)
- Benzyl group
- In organic chemistry, benzyl is the substituent or molecular fragment possessing the structure. Also: benzyl. Definition: first sentence of Wikipedia: Benzyl group (CC BY-SA 4.0)
- Beta oxidation
- In biochemistry and metabolism, beta oxidation (also β-oxidation) is the catabolic process by which fatty acid molecules are broken down in the cytosol in prokaryotes and in the mitochondria in eukaryotes to generate acetyl-CoA. Definition: first sentence of Wikipedia: Beta oxidation (CC BY-SA 4.0)
- Bilayer
- A bilayer is a double layer of closely packed atoms or molecules. Definition: first sentence of Wikipedia: Bilayer (CC BY-SA 4.0)
- Bile acid
- Bile acids are steroid acids found predominantly in the bile of mammals and other vertebrates. Definition: first sentence of Wikipedia: Bile acid (CC BY-SA 4.0)
- Biochemistry
- Biochemistry, or biological chemistry (distinct from chemical biology), is the study of chemical processes within and relating to living organisms. Also: biochemical, biochemically. Definition: first sentence of Wikipedia: Biochemistry (CC BY-SA 4.0)
- Bioenergetics
- Bioenergetics is a field in biochemistry and cell biology that concerns energy flow through living systems. Also: cellular energy. Definition: first sentence of Wikipedia: Bioenergetics (CC BY-SA 4.0)
- Biogeography
- Biogeography is the study of the distribution of species and ecosystems in geographic space and throughout geological time. Definition: first sentence of Wikipedia: Biogeography (CC BY-SA 4.0)
- Bioinformatics
- Bioinformatics is an interdisciplinary field of science that develops computational methods and software tools for understanding biological data, especially when the data sets are large and complex. Definition: first sentence of Wikipedia: Bioinformatics (CC BY-SA 4.0)
- Biological dispersal
- Biological dispersal refers to both the movement of individuals (animals, plants, fungi, bacteria, etc.) from their birth site to their breeding site ('natal dispersal') and the movement from one breeding site to another ('breeding dispersal'). Also: dispersal. Definition: first sentence of Wikipedia: Biological dispersal (CC BY-SA 4.0)
- Biological pigment
- A biological pigment, also known simply as a pigment or biochrome, is a substance produced by living organisms that have a color resulting from selective color absorption. Also: pigments. Definition: first sentence of Wikipedia: Biological pigment (CC BY-SA 4.0)
- Biological process
- A biological process is a process necessary for an organism to live, and therefore shapes its capacity to interact with its environment. Definition: first sentence of Wikipedia: Biological process (CC BY-SA 4.0)
- Biology
- Biology is the scientific study of life and living organisms. Definition: first sentence of Wikipedia: Biology (CC BY-SA 4.0)
- Biomolecular structure
- Biomolecular structure is the intricate folded, three-dimensional shape that is formed by a molecule of protein, DNA, or RNA, and that is important to its function. Also: structure. Definition: first sentence of Wikipedia: Biomolecular structure (CC BY-SA 4.0)
- Biomolecule
- A biomolecule or biological molecule is loosely defined as a molecule produced by a living organism and essential to one or more typically biological processes. Also: biomolecules. Definition: first sentence of Wikipedia: Biomolecule (CC BY-SA 4.0)
- Biopolymer
- Biopolymers are natural polymers produced by the cells of living organisms. Also: biopolymers. Definition: first sentence of Wikipedia: Biopolymer (CC BY-SA 4.0)
- Birth control
- Birth control, also known as contraception, anticonception, and fertility control, is the use of methods or devices to prevent pregnancy. Also: contraception. Definition: first sentence of Wikipedia: Birth control (CC BY-SA 4.0)
- Blastocyst
- The blastocyst is a structure formed in the early embryonic development of mammals. Definition: first sentence of Wikipedia: Blastocyst (CC BY-SA 4.0)
- Blood
- Blood is a body fluid in the circulatory system of humans and other vertebrates that delivers necessary substances such as nutrients and oxygen to the cells of the body, and transports metabolic waste products away from those same cells. Also: bloodstream. Definition: first sentence of Wikipedia: Blood (CC BY-SA 4.0)
- Blood bank
- A blood bank is a center where blood gathered as a result of blood donation is stored and preserved for later use in blood transfusion. Definition: first sentence of Wikipedia: Blood bank (CC BY-SA 4.0)
- Blood cell
- A blood cell (also called a hemocyte or hematocyte) is a cell produced through hematopoiesis and found mainly in the blood. Definition: first sentence of Wikipedia: Blood cell (CC BY-SA 4.0)
- Blood plasma
- Blood plasma is a light amber-colored liquid component of blood in which blood cells are absent, but which contains proteins and other constituents of whole blood in suspension. Definition: first sentence of Wikipedia: Blood plasma (CC BY-SA 4.0)
- Blowback (firearms)
- Blowback is a system of operation for self-loading firearms that obtains energy from the motion of the cartridge case as it is pushed to the rear by expanding gas created by the ignition of the propellant charge. Also: blowback. Definition: first sentence of Wikipedia: Blowback (firearms) (CC BY-SA 4.0)
- Bone marrow
- Bone marrow is a semi-solid tissue found within the spongy (also known as cancellous) portions of bones. Definition: first sentence of Wikipedia: Bone marrow (CC BY-SA 4.0)
- Brackish water
- Brackish water, sometimes termed brack water, is water occurring in a natural environment that has more salinity than freshwater, but not as much as seawater. Also: brackish. Definition: first sentence of Wikipedia: Brackish water (CC BY-SA 4.0)
- Brain
- The brain is an organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals. Definition: first sentence of Wikipedia: Brain (CC BY-SA 4.0)
- Buffer solution
- A buffer solution is a solution where the pH does not change significantly on dilution or if a small amount of strong acid or base is added to it at constant temperature. Also: buffer. Definition: first sentence of Wikipedia: Buffer solution (CC BY-SA 4.0)
- Burst mode (weapons)
- In automatic firearms, burst mode or burst-fire is a firing mode enabling the shooter to fire a predetermined number of rounds, usually two or three rounds on handheld weapons to fifty or more rounds on autocannons, with a single pull of the trigger. Also: 3-round burst, burst. Definition: first sentence of Wikipedia: Burst mode (weapons) (CC BY-SA 4.0)
- Bycatch
- Bycatch (or by-catch), in the fishing industry, is a fish or other marine species that is caught unintentionally while fishing for specific species or sizes of wildlife. Definition: first sentence of Wikipedia: Bycatch (CC BY-SA 4.0)
C
- Calcium
- Calcium is a chemical element; it has symbol Ca and atomic number 20. Definition: first sentence of Wikipedia: Calcium (CC BY-SA 4.0)
- Calcium-sensing receptor
- The calcium-sensing receptor (CaSR) is a Class C G-protein coupled receptor which senses extracellular levels of calcium ions. Also: calcium ion. Definition: first sentence of Wikipedia: Calcium-sensing receptor (CC BY-SA 4.0)
- Canadian Hockey League
- The Canadian Hockey League (CHL; Ligue canadienne de hockey, LCH) is an umbrella organization that represents the three Canada-based major junior ice hockey leagues. Also: major junior. Definition: first sentence of Wikipedia: Canadian Hockey League (CC BY-SA 4.0)
- Cancer
- Cancer is a group of diseases involving uncontrolled cell growth typically resulting in tumors with the potential to invade or spread to other parts of the body. Definition: first sentence of Wikipedia: Cancer (CC BY-SA 4.0)
- Cancer cell
- Cancer cells are cells that divide continually, forming solid tumors or flooding the blood or lymph with abnormal cells. Also: cancer cells. Definition: first sentence of Wikipedia: Cancer cell (CC BY-SA 4.0)
- Capsid
- A capsid is the protein shell of a virus, enclosing its genetic material. Definition: first sentence of Wikipedia: Capsid (CC BY-SA 4.0)
- Carbon
- Carbon is a chemical element; it has symbol C and atomic number 6. Definition: first sentence of Wikipedia: Carbon (CC BY-SA 4.0)
- Carbon compounds
- Carbon compounds are chemical substances containing carbon. Also: carbon-based compounds. Definition: first sentence of Wikipedia: Carbon compounds (CC BY-SA 4.0)
- Carbon dioxide
- Carbon dioxide is a chemical compound with the chemical formula '. Definition: first sentence of Wikipedia: Carbon dioxide (CC BY-SA 4.0)
- Cardiac muscle
- Cardiac muscle (also called heart muscle or myocardium) is one of three types of vertebrate muscle tissues, the others being skeletal muscle and smooth muscle. Definition: first sentence of Wikipedia: Cardiac muscle (CC BY-SA 4.0)
- Carnitine
- Carnitine is a quaternary ammonium compound involved in metabolism in most mammals, plants, and some bacteria. Definition: first sentence of Wikipedia: Carnitine (CC BY-SA 4.0)
- Cartilage
- Cartilage is a resilient and smooth type of connective tissue. Definition: first sentence of Wikipedia: Cartilage (CC BY-SA 4.0)
- Casein
- Casein is a family of related phosphoproteins (αS1, aS2, β, κ) that are commonly found in mammalian milk, comprising about 80% of the proteins in cow's milk and between 20% and 60% of the proteins in human milk. Definition: first sentence of Wikipedia: Casein (CC BY-SA 4.0)
- Caspase
- Caspases (cysteine-aspartic proteases, cysteine aspartases or cysteine-dependent aspartate-directed proteases) are a family of protease enzymes playing essential roles in programmed cell death. Definition: first sentence of Wikipedia: Caspase (CC BY-SA 4.0)
- Catalase
- Catalase is a common enzyme found in nearly all living organisms exposed to oxygen (such as bacteria, plants, and animals) which catalyzes the decomposition of hydrogen peroxide to water and oxygen. Definition: first sentence of Wikipedia: Catalase (CC BY-SA 4.0)
- Catalysis
- Catalysis is the increase in rate of a chemical reaction due to an added substance known as a catalyst. Also: catalysts, catalytic, catalyzes. Definition: first sentence of Wikipedia: Catalysis (CC BY-SA 4.0)
- Catecholamine
- A catecholamine, most typically a 3,4-dihydroxyphenethylamine, is a monoamine neurotransmitter, an organic compound that has a catechol (benzene with two hydroxyl side groups next to each other) and a side-chain amine. Definition: first sentence of Wikipedia: Catecholamine (CC BY-SA 4.0)
- Cell culture
- Cell culture or tissue culture is the process by which cells are grown under controlled conditions, generally outside of their natural environment. Also: cultured. Definition: first sentence of Wikipedia: Cell culture (CC BY-SA 4.0)
- Cell fractionation
- In cell biology, cell fractionation is the process used to separate cellular components while preserving individual functions of each component. Definition: first sentence of Wikipedia: Cell fractionation (CC BY-SA 4.0)
- Cell growth
- Cell growth refers to an increase in the total mass of a cell, including both cytoplasmic, nuclear and organelle volume. Definition: first sentence of Wikipedia: Cell growth (CC BY-SA 4.0)
- Cell membrane
- The cell membrane (also known as the plasma membrane or cytoplasmic membrane, and historically referred to as the plasmalemma) is a semipermeable biological membrane that separates and protects the interior of a cell from the outside environment (the extracellular space). Also: membrane. Definition: first sentence of Wikipedia: Cell membrane (CC BY-SA 4.0)
- Cell migration
- Cell migration is the movement of cells, either individually or as a group. Also: migrate. Definition: first sentence of Wikipedia: Cell migration (CC BY-SA 4.0)
- Cell nucleus
- The cell nucleus is a membrane-bound organelle found in eukaryotic cells. Also: nuclear, nucleus. Definition: first sentence of Wikipedia: Cell nucleus (CC BY-SA 4.0)
- Cell proliferation
- Cell proliferation is the process in multicellular organisms by which a cell grows and divides to produce two daughter cells. Also: proliferation. Definition: first sentence of Wikipedia: Cell proliferation (CC BY-SA 4.0)
- Cell signaling
- Cell signaling (cell signalling in British English) is the biological process by which a cell interacts with itself, with other cells, and with the environment. Also: signal, signals. Definition: first sentence of Wikipedia: Cell signaling (CC BY-SA 4.0)
- Cellular senescence
- Cellular senescence is a phenomenon characterized by the cessation of cell division. Definition: first sentence of Wikipedia: Cellular senescence (CC BY-SA 4.0)
- Cephalopod
- A cephalopod is any member of the molluscan class Cephalopoda (Greek plural κεφαλόποδες, kephalópodes; "head-feet") such as a squid, octopus, cuttlefish, or nautilus. Also: cephalopods. Definition: first sentence of Wikipedia: Cephalopod (CC BY-SA 4.0)
- CFU-GEMM
- CFU-GEMM is a colony forming unit that generates myeloid cells. Also: myeloid progenitor cells. Definition: first sentence of Wikipedia: CFU-GEMM (CC BY-SA 4.0)
- Chaperone (protein)
- In molecular biology, molecular chaperones are proteins that assist the conformational folding or unfolding of proteins or macromolecular protein complexes. Also: chaperone protein. Definition: first sentence of Wikipedia: Chaperone (protein) (CC BY-SA 4.0)
- Chemical ecology
- Chemical ecology is a vast and interdisciplinary field utilizing biochemistry, biology, ecology, and organic chemistry for explaining observed interactions of living things and their environment through chemical compounds (e.g. ecosystem resilience and biodiversity). Definition: first sentence of Wikipedia: Chemical ecology (CC BY-SA 4.0)
- Chemical energy
- Chemical energy is the energy of chemical substances that is released when the substances undergo a chemical reaction and transform into other substances. Definition: first sentence of Wikipedia: Chemical energy (CC BY-SA 4.0)
- Chemical reaction
- A chemical reaction is a process that leads to the chemical transformation of one set of chemical substances to another. Also: reaction. Definition: first sentence of Wikipedia: Chemical reaction (CC BY-SA 4.0)
- Chemoreceptor
- A chemoreceptor, also known as chemosensor, is a specialized sensory receptor which transduces a chemical substance (endogenous or induced) to generate a biological signal. Also: chemoreceptors. Definition: first sentence of Wikipedia: Chemoreceptor (CC BY-SA 4.0)
- Chia seed
- Chia seeds are the edible seeds of Salvia hispanica, a flowering plant in the mint family (Lamiaceae) native to central and southern Mexico, or of the related Salvia columbariae, Salvia polystachia, or Salvia tiliifolia. Also: chia seeds. Definition: first sentence of Wikipedia: Chia seed (CC BY-SA 4.0)
- Chirality (chemistry)
- In chemistry, a molecule or ion is called chiral if it cannot be superposed on its mirror image by any combination of rotations, translations, and some conformational changes. Also: chiral. Definition: first sentence of Wikipedia: Chirality (chemistry) (CC BY-SA 4.0)
- Chlamydomonadales
- Chlamydomonadales, also known as Volvocales, are an order of flagellated or pseudociliated green algae, specifically of the Chlorophyceae. Also: volvocine. Definition: first sentence of Wikipedia: Chlamydomonadales (CC BY-SA 4.0)
- Choline
- Choline is a cation with the chemical formula. Definition: first sentence of Wikipedia: Choline (CC BY-SA 4.0)
- Chondrichthyes
- Chondrichthyes is a class of jawed fish that contains the cartilaginous fish or chondrichthyans, which all have skeletons primarily composed of cartilage. Also: cartilaginous fish. Definition: first sentence of Wikipedia: Chondrichthyes (CC BY-SA 4.0)
- Chromoplast
- Chromoplasts are plastids, heterogeneous organelles responsible for pigment synthesis and storage in specific photosynthetic eukaryotes. Also: chromoplasts. Definition: first sentence of Wikipedia: Chromoplast (CC BY-SA 4.0)
- Chylomicron
- Chylomicrons (from the Greek χυλός, chylós, meaning juice (of plants or animals), and micron, meaning small), also known as ultra low-density lipoproteins (ULDL), are lipoprotein particles that consist of triglycerides (83–92%), phospholipids (6–12%), cholesterol (1–3%), and proteins (1–2%). Also: chylomicrons. Definition: first sentence of Wikipedia: Chylomicron (CC BY-SA 4.0)
- Ciliate
- The ciliates are a group of alveolates characterized by the presence of hair-like organelles called cilia, which are identical in structure to eukaryotic flagella, but are in general shorter and present in much larger numbers, with a different undulating pattern than flagella. Also: ciliates. Definition: first sentence of Wikipedia: Ciliate (CC BY-SA 4.0)
- Cis-regulatory element
- Cis-regulatory elements (CREs) or cis-regulatory modules (CRMs) are regions of non-coding DNA which regulate the transcription of neighboring genes. Also: cis-regulatory elements. Definition: first sentence of Wikipedia: Cis-regulatory element (CC BY-SA 4.0)
- Cisterna
- A cisternae is a flattened membrane vesicle found in the endoplasmic reticulum and Golgi apparatus. Also: cisternae. Definition: first sentence of Wikipedia: Cisterna (CC BY-SA 4.0)
- Clade
- In biology, a clade, also known as a monophyletic group or natural group, is a group of organisms that is composed of a common ancestor and all of its descendants. Definition: first sentence of Wikipedia: Clade (CC BY-SA 4.0)
- Clasper
- In biology, a clasper is a male anatomical structure found in some groups of animals, used in mating. Also: claspers. Definition: first sentence of Wikipedia: Clasper (CC BY-SA 4.0)
- Cleavage stimulation factor
- Cleavage stimulatory factor or cleavage stimulation factor (CstF or CStF) is a heterotrimeric protein involved in the cleavage of the 3' signaling region from a newly synthesized pre-messenger RNA (mRNA) molecule. Definition: first sentence of Wikipedia: Cleavage stimulation factor (CC BY-SA 4.0)
- Closed bolt
- A semi or fully automatic firearm which is said to fire from a closed bolt or closed breech is one where, when ready to fire, a round is in the chamber and the bolt and working parts are forward in battery. Definition: first sentence of Wikipedia: Closed bolt (CC BY-SA 4.0)
- Cofactor (biochemistry)
- A cofactor is a non-protein chemical compound or metallic ion that is required for an enzyme's role as a catalyst. Also: cofactors. Definition: first sentence of Wikipedia: Cofactor (biochemistry) (CC BY-SA 4.0)
- Cognition
- Cognition encompasses mental processes that deal with knowledge. Definition: first sentence of Wikipedia: Cognition (CC BY-SA 4.0)
- Collagen
- Collagen is the main structural protein in the extracellular matrix of the connective tissues of many animals. Definition: first sentence of Wikipedia: Collagen (CC BY-SA 4.0)
- Commercial fishing
- Commercial fishing is the activity of catching fish and other seafood for commercial profit, mostly from wild fisheries. Also: commercial fisheries. Definition: first sentence of Wikipedia: Commercial fishing (CC BY-SA 4.0)
- Complementarity (molecular biology)
- In molecular biology, complementarity describes a relationship between two structures each following the lock-and-key principle. Also: complementary. Definition: first sentence of Wikipedia: Complementarity (molecular biology) (CC BY-SA 4.0)
- Computational biology
- Computational biology is a interdisciplinary field involving the study of biological systems through the application of computer science, data analysis, mathematical modeling and computational simulations. Definition: first sentence of Wikipedia: Computational biology (CC BY-SA 4.0)
- Concentration
- In chemistry, concentration is the abundance of a constituent divided by the total volume of a mixture. Definition: first sentence of Wikipedia: Concentration (CC BY-SA 4.0)
- Condensation reaction
- In organic chemistry, a condensation reaction is a type of chemical reaction in which two molecules are combined to form a single molecule, usually with the loss of a small molecule such as water. Also: condensation reactions. Definition: first sentence of Wikipedia: Condensation reaction (CC BY-SA 4.0)
- Cone cell
- Cone cells or cones are photoreceptor cells in the retina of the vertebrate eye. Also: cones. Definition: first sentence of Wikipedia: Cone cell (CC BY-SA 4.0)
- Consensus sequence
- In molecular biology and bioinformatics, the consensus sequence (or canonical sequence) is the calculated sequence of most frequent residues, either nucleotide or amino acid, found at each position in a sequence alignment. Definition: first sentence of Wikipedia: Consensus sequence (CC BY-SA 4.0)
- Conserved sequence
- In evolutionary biology, conserved sequences are identical or similar sequences in nucleic acids (DNA and RNA) or proteins across species (orthologous sequences), or within a genome (paralogous sequences), or between donor and receptor taxa (xenologous sequences). Also: conserved. Definition: first sentence of Wikipedia: Conserved sequence (CC BY-SA 4.0)
- Continental shelf
- A continental shelf is a portion of a continent that is submerged under an area of relatively shallow water, known as a shelf sea. Definition: first sentence of Wikipedia: Continental shelf (CC BY-SA 4.0)
- Contractile vacuole
- A contractile vacuole (CV) is a sub-cellular structure (organelle) involved in osmoregulation. Definition: first sentence of Wikipedia: Contractile vacuole (CC BY-SA 4.0)
- Coordination complex
- A coordination complex is a chemical compound consisting of a central atom or ion, which is usually metallic and is called the coordination centre, and a surrounding array of bound molecules or ions, that are in turn known as ligands or complexing agents. Also: complex. Definition: first sentence of Wikipedia: Coordination complex (CC BY-SA 4.0)
- Copepod
- Copepods are a group of small crustaceans found in nearly every freshwater and saltwater habitat. Definition: first sentence of Wikipedia: Copepod (CC BY-SA 4.0)
- Corticosteroid
- Corticosteroids are a class of steroid hormones that are produced in the adrenal cortex of vertebrates, and also their synthetic analogues. Also: corticosteroids. Definition: first sentence of Wikipedia: Corticosteroid (CC BY-SA 4.0)
- Cosmetic industry
- The cosmetic industry describes the industry that manufactures and distributes cosmetic products. Also: cosmetic. Definition: first sentence of Wikipedia: Cosmetic industry (CC BY-SA 4.0)
- Costamere
- The costamere is a structural-functional component of striated muscle cells which connects the sarcomere of the muscle to the cell membrane (i.e. the sarcolemma). Definition: first sentence of Wikipedia: Costamere (CC BY-SA 4.0)
- Countershading
- Countershading, or Thayer's law, is a method of camouflage in which an animal's coloration is darker on the top or upper side and lighter on the underside of the body. Definition: first sentence of Wikipedia: Countershading (CC BY-SA 4.0)
- Covalent bond
- A covalent bond is a chemical bond that involves the sharing of electrons to form electron pairs between atoms. Also: covalent. Definition: first sentence of Wikipedia: Covalent bond (CC BY-SA 4.0)
- Crista
- A crista is a fold in the inner membrane of a mitochondrion. Also: cristae. Definition: first sentence of Wikipedia: Crista (CC BY-SA 4.0)
- Cross section (geometry)
- In geometry and science, a cross section is the non-empty intersection of a solid body in three-dimensional space with a plane, or the analog in higher-dimensional spaces. Also: cross section. Definition: first sentence of Wikipedia: Cross section (geometry) (CC BY-SA 4.0)
- Cross-link
- In chemistry and biology, a cross-link is a bond or a short sequence of bonds that links one polymer chain to another. Also: crosslinking. Definition: first sentence of Wikipedia: Cross-link (CC BY-SA 4.0)
- Crustacean
- Crustaceans (from Latin word "crustacea" meaning: "those with shells" or "crusted ones") are mandibulate arthropods that are traditionally a part of the paraphyletic subphylum Crustacea. Also: crustaceans. Definition: first sentence of Wikipedia: Crustacean (CC BY-SA 4.0)
- Cryo-electron microscopy
- Cryogenic electron microscopy (cryo-EM) is a transmission electron microscopy technique applied to samples cooled to cryogenic temperatures. Definition: first sentence of Wikipedia: Cryo-electron microscopy (CC BY-SA 4.0)
- Cryptobiosis
- Cryptobiosis or anabiosis is a metabolic state in extremophilic organisms in response to adverse environmental conditions such as desiccation, freezing, and oxygen deficiency. Also: anabiosis. Definition: first sentence of Wikipedia: Cryptobiosis (CC BY-SA 4.0)
- Crystal
- A crystal or crystalline solid is a solid material whose constituents (such as atoms, molecules, or ions) are arranged in a highly ordered microscopic structure, forming a crystal lattice that extends in all directions. Also: crystalline. Definition: first sentence of Wikipedia: Crystal (CC BY-SA 4.0)
- Crystal violet
- Crystal violet or gentian violet, also known as methyl violet 10B or hexamethyl pararosaniline chloride, is a triarylmethane dye used as a histological stain and in Gram's method of classifying bacteria. Definition: first sentence of Wikipedia: Crystal violet (CC BY-SA 4.0)
- Curare
- Curare (or; or) is a common name for various alkaloid arrow poisons originating from plant extracts. Definition: first sentence of Wikipedia: Curare (CC BY-SA 4.0)
- Current source
- A current source is an electronic circuit that delivers or absorbs an electric current which is independent of the voltage across it. Also: current sources. Definition: first sentence of Wikipedia: Current source (CC BY-SA 4.0)
- Cutin
- Cutin is one of two waxy polymers that are the main components of the plant cuticle, which covers all aerial surfaces of plants, the other being cutan. Definition: first sentence of Wikipedia: Cutin (CC BY-SA 4.0)
- Cyanobiont
- Cyanobionts are cyanobacteria that live in symbiosis with a wide range of organisms such as terrestrial or aquatic plants; as well as, algal and fungal species. Definition: first sentence of Wikipedia: Cyanobiont (CC BY-SA 4.0)
- Cyclic compound
- A cyclic compound (or ring compound) is a chemical compound which includes a ring. Also: cyclization. Definition: first sentence of Wikipedia: Cyclic compound (CC BY-SA 4.0)
- Cycloartenol
- Cycloartenol is an important triterpenoid often found in plants. Definition: first sentence of Wikipedia: Cycloartenol (CC BY-SA 4.0)
- Cyclohexane
- Cyclohexane is a cycloalkane with the molecular formula. Definition: first sentence of Wikipedia: Cyclohexane (CC BY-SA 4.0)
- Cyclopentane
- Cyclopentane (also called C pentane) is a highly flammable alicyclic hydrocarbon with chemical formula C5H10 and CAS number 287-92-3, consisting of a ring of five carbon atoms each bonded with two hydrogen atoms above and below the plane. Definition: first sentence of Wikipedia: Cyclopentane (CC BY-SA 4.0)
- Cysteine
- Cysteine is a semiessential proteinogenic amino acid with the formula. Also: cysteinated. Definition: first sentence of Wikipedia: Cysteine (CC BY-SA 4.0)
- Cytokine
- Cytokines are a broad and loose category of small proteins (~5–25 kDa) important in cell signaling. Definition: first sentence of Wikipedia: Cytokine (CC BY-SA 4.0)
- Cytosine
- Cytosine (symbol C or Cyt) is one of the four nucleotide bases found in DNA and RNA, along with adenine, guanine, and thymine (uracil in RNA). Definition: first sentence of Wikipedia: Cytosine (CC BY-SA 4.0)
- Cytosol
- The cytosol, also known as cytoplasmic matrix or groundplasm, is one of the liquids found inside cells (intracellular fluid (ICF)). Definition: first sentence of Wikipedia: Cytosol (CC BY-SA 4.0)
- Cytotoxicity
- Cytotoxicity refers to the capacity of a substance or agent to damage or kill living cells, reflecting a critical parameter in pharmacology, toxicology, and biomedicine. Also: cytotoxic. Definition: first sentence of Wikipedia: Cytotoxicity (CC BY-SA 4.0)
D
- Dalton (unit)
- The dalton (symbol: Da), or unified atomic mass unit (symbol: u), is a unit of mass defined as 1/12 of the mass of an unbound neutral atom of carbon-12 in its nuclear and electronic ground state and at rest. Also: daltons. Definition: first sentence of Wikipedia: Dalton (unit) (CC BY-SA 4.0)
- De novo synthesis
- In chemistry, de novo synthesis is the synthesis of complex molecules from simple molecules such as sugars or amino acids, as opposed to recycling after partial degradation. Also: de novo. Definition: first sentence of Wikipedia: De novo synthesis (CC BY-SA 4.0)
- Death
- It is the irreversible cessation of biological functions that sustain a living organism; however, the identification of the moment of death presents certain difficulties. Definition: first sentence of Wikipedia: Death (CC BY-SA 4.0)
- Defenceman
- Defence or defense (in American English) in ice hockey is a player position that is primarily responsible for preventing the opposing team from scoring. Also: defenseman. Definition: first sentence of Wikipedia: Defenceman (CC BY-SA 4.0)
- Degradative enzyme
- A degradative enzyme is an enzyme (in a broader sense a protein) which degrades biological molecules. Also: degradative enzymes. Definition: first sentence of Wikipedia: Degradative enzyme (CC BY-SA 4.0)
- Delta endotoxins
- Delta endotoxins (δ-endotoxins) are a family of pore-forming toxins produced by Bacillus thuringiensis species of bacteria. Also: delta endotoxin. Definition: first sentence of Wikipedia: Delta endotoxins (CC BY-SA 4.0)
- Demersal fish
- Demersal fish, also known as groundfish, live and feed on or near the bottom of seas or lakes (the demersal zone). Also: demersal. Definition: first sentence of Wikipedia: Demersal fish (CC BY-SA 4.0)
- Denaturation (biochemistry)
- If proteins in a living cell are denatured, this results in disruption of cell activity and possibly cell death. Also: denaturing. Definition: first sentence of Wikipedia: Denaturation (biochemistry) (CC BY-SA 4.0)
- Dendrite
- A dendrite (from Greek δένδρον déndron, "tree") or dendron is a branched cytoplasmic process extending from a nerve cell; it propagates the electrochemical stimulation received from other neural cells to the cell body, or soma, of the neuron from which the dendrites project. Also: dendrites. Definition: first sentence of Wikipedia: Dendrite (CC BY-SA 4.0)
- Dendrodendritic synapse
- Dendrodendritic synapses are connections between the dendrites of two different neurons. Also: dendrodendritic synapses. Definition: first sentence of Wikipedia: Dendrodendritic synapse (CC BY-SA 4.0)
- Deoxyribose
- Deoxyribose, or more precisely 2-deoxyribose, is a monosaccharide with idealized formula H−(C=O)−(CH2)−(CHOH)3−H. Its name indicates that it is a deoxy sugar, meaning that it is derived from the sugar ribose by loss of a hydroxy group. Definition: first sentence of Wikipedia: Deoxyribose (CC BY-SA 4.0)
- Depolarization
- In biology, depolarization or hypopolarization is a change within a cell, during which the cell undergoes a shift in electric charge distribution, resulting in less negative charge inside the cell compared to the outside. Definition: first sentence of Wikipedia: Depolarization (CC BY-SA 4.0)
- Deprotonation
- Deprotonation (or dehydronation) is the removal (transfer) of a proton (or hydron, or hydrogen cation), (H+) from a Brønsted–Lowry acid in an acid–base reaction. Also: deprotonated. Definition: first sentence of Wikipedia: Deprotonation (CC BY-SA 4.0)
- Desiccation
- Desiccation is the state of extreme dryness, or the process of extreme drying. Definition: first sentence of Wikipedia: Desiccation (CC BY-SA 4.0)
- Detergent
- A detergent is a product for cleaning that contains surfactants plus other components. Also: detergents. Definition: first sentence of Wikipedia: Detergent (CC BY-SA 4.0)
- Developmental biology
- Developmental biology is the scientific study of the processes by which animals and plants grow and develop. Also: development. Definition: first sentence of Wikipedia: Developmental biology (CC BY-SA 4.0)
- Diaminopimelic acid
- Diaminopimelic acid (DAP) is an amino acid, representing an epsilon-carboxy derivative of lysine. meso-α,ε-Diaminopimelic acid is the last intermediate in the biosynthesis of lysine and undergoes decarboxylation by diaminopimelate decarboxylase to give the final product. Also: diaminopimelate. Definition: first sentence of Wikipedia: Diaminopimelic acid (CC BY-SA 4.0)
- Diatom
- A diatom (Neo-Latin diatoma) is any member of a large group comprising several genera of algae, specifically microalgae, found in the oceans, waterways and soils of the world. Also: diatoms. Definition: first sentence of Wikipedia: Diatom (CC BY-SA 4.0)
- Diethyl malonate
- Diethyl malonate, also known as DEM, is the diethyl ester of malonic acid. Definition: first sentence of Wikipedia: Diethyl malonate (CC BY-SA 4.0)
- Differential centrifugation
- In biochemistry and cell biology, differential centrifugation (also known as differential velocity centrifugation) is a common procedure used to separate organelles and other sub-cellular particles based on their sedimentation rate. Definition: first sentence of Wikipedia: Differential centrifugation (CC BY-SA 4.0)
- Diffusion
- Diffusion is the net movement of anything (for example, atoms, ions, molecules, energy) generally from a region of higher concentration to a region of lower concentration. Also: diffuse. Definition: first sentence of Wikipedia: Diffusion (CC BY-SA 4.0)
- Digestion
- Digestion is the breakdown of large insoluble food compounds into small water-soluble components so that they can be absorbed into the blood plasma. Also: digestive. Definition: first sentence of Wikipedia: Digestion (CC BY-SA 4.0)
- Diglyceride
- A diglyceride, or diacylglycerol (DAG), is a glyceride consisting of two fatty acid chains covalently bonded to a glycerol molecule through ester linkages. Also: diacylglycerol, diglycerides. Definition: first sentence of Wikipedia: Diglyceride (CC BY-SA 4.0)
- Diminutive
- A diminutive is a word obtained by modifying a root word to convey a slighter degree of its root meaning, either to convey the smallness of the object or quality named, or to convey a sense of intimacy or endearment, and sometimes to belittle something or someone. Definition: first sentence of Wikipedia: Diminutive (CC BY-SA 4.0)
- Dipicolinic acid
- Dipicolinic acid (pyridine-2,6-dicarboxylic acid or PDC and DPA) is a chemical compound which plays a role in the heat resistance of bacterial endospores. Definition: first sentence of Wikipedia: Dipicolinic acid (CC BY-SA 4.0)
- Direct impingement
- Direct impingement is a type of gas operation for a firearm that utilizes gas from a fired cartridge to impart force on the bolt carrier or slide assembly to cycle the action. Also: gas impingement. Definition: first sentence of Wikipedia: Direct impingement (CC BY-SA 4.0)
- Directionality (molecular biology)
- Directionality, in molecular biology and biochemistry, is the end-to-end chemical orientation of a single strand of nucleic acid. Also: directionality, directionally. Definition: first sentence of Wikipedia: Directionality (molecular biology) (CC BY-SA 4.0)
- Disaccharide
- A disaccharide (also called a double sugar or biose) is the sugar formed when two monosaccharides are joined by glycosidic linkage. Also: disaccharides. Definition: first sentence of Wikipedia: Disaccharide (CC BY-SA 4.0)
- Disease
- A disease is a particular abnormal condition that adversely affects the structure or function of all or part of an organism and is not immediately due to any external injury. Also: diseases. Definition: first sentence of Wikipedia: Disease (CC BY-SA 4.0)
- Dissociation (chemistry)
- Dissociation in chemistry is a general process in which molecules (or ionic compounds such as salts, or complexes) separate or split into other things such as atoms, ions, or radicals, usually in a reversible manner. Also: dissociation. Definition: first sentence of Wikipedia: Dissociation (chemistry) (CC BY-SA 4.0)
- Diurnality
- Diurnality is a form of plant and animal behavior characterized by activity during daytime, with a period of sleeping or other inactivity at night. Also: diurnal. Definition: first sentence of Wikipedia: Diurnality (CC BY-SA 4.0)
- DNA
- Deoxyribonucleic acid is a polymer composed of two polynucleotide chains that coil around each other to form a double helix. Also: deoxyribonucleic acid. Definition: first sentence of Wikipedia: DNA (CC BY-SA 4.0)
- Docosahexaenoic acid
- Docosahexaenoic acid (DHA) is an omega−3 fatty acid that is an important component of the human brain, cerebral cortex, skin, and retina. Definition: first sentence of Wikipedia: Docosahexaenoic acid (CC BY-SA 4.0)
- Dopamine
- Dopamine (DA, a contraction of 3,4-dihydroxyphenethylamine) is a neuromodulatory molecule that plays several important roles in cells. Definition: first sentence of Wikipedia: Dopamine (CC BY-SA 4.0)
- Dormancy
- Dormancy is a period in an organism's life cycle when growth, development, and (in animals) physical activity are temporarily stopped. Also: dormant. Definition: first sentence of Wikipedia: Dormancy (CC BY-SA 4.0)
- Dorsal fin
- A dorsal fin is a fin on the back of most marine and freshwater vertebrates. Definition: first sentence of Wikipedia: Dorsal fin (CC BY-SA 4.0)
- Double bond
- In chemistry, a double bond is a covalent bond between two atoms involving four bonding electrons as opposed to two in a single bond. Definition: first sentence of Wikipedia: Double bond (CC BY-SA 4.0)
- Dry matter
- The dry matter or dry weight is a measure of the mass of a completely dried substance. Also: dry weight. Definition: first sentence of Wikipedia: Dry matter (CC BY-SA 4.0)
- Dual-polarization interferometry
- Dual-polarization interferometry (DPI) is an analytical technique that probes molecular layers adsorbed to the surface of a waveguide using the evanescent wave of a laser beam. Also: dual polarisation interferometry. Definition: first sentence of Wikipedia: Dual-polarization interferometry (CC BY-SA 4.0)
E
- Ecosystem
- An ecosystem (or ecological system) is a system formed by organisms in interaction with their environment, where the biotic and abiotic components are linked together through nutrient cycles and energy flows. Definition: first sentence of Wikipedia: Ecosystem (CC BY-SA 4.0)
- Ectoderm
- The ectoderm is one of the three primary germ layers formed in early embryonic development. Definition: first sentence of Wikipedia: Ectoderm (CC BY-SA 4.0)
- Eicosapentaenoic acid
- Eicosapentaenoic acid (EPA; also icosapentaenoic acid) is an omega−3 fatty acid. Definition: first sentence of Wikipedia: Eicosapentaenoic acid (CC BY-SA 4.0)
- Elasmobranchii
- Elasmobranchii is a subclass of Chondrichthyes or cartilaginous fish, including modern sharks (division Selachii), and batomorphs (division Batomorphi, including rays, skates, and sawfish). Also: elasmobranch, elasmobranchs. Definition: first sentence of Wikipedia: Elasmobranchii (CC BY-SA 4.0)
- Electrochemical gradient
- An electrochemical gradient is a gradient of electrochemical potential, usually for an ion that can move across a membrane. Definition: first sentence of Wikipedia: Electrochemical gradient (CC BY-SA 4.0)
- Electrochemistry
- Electrochemistry is the branch of physical chemistry concerned with the relationship between electrical potential difference and identifiable chemical change. Also: electrochemical. Definition: first sentence of Wikipedia: Electrochemistry (CC BY-SA 4.0)
- Electron
- The electron (', or ' in nuclear reactions) is a subatomic particle whose electric charge is negative one elementary charge. Also: electrons. Definition: first sentence of Wikipedia: Electron (CC BY-SA 4.0)
- Electron tomography
- Electron tomography (ET) is a tomography technique for obtaining detailed 3D structures of sub-cellular, macro-molecular, or materials specimens. Definition: first sentence of Wikipedia: Electron tomography (CC BY-SA 4.0)
- Electron transfer
- Electron transfer (ET) occurs when an electron relocates from an atom, ion, or molecule, to another such chemical entity. Definition: first sentence of Wikipedia: Electron transfer (CC BY-SA 4.0)
- Electroreception and electrogenesis
- Electroreception and electrogenesis are the closely related biological abilities to perceive electrical stimuli and to generate electric fields. Also: electroreception. Definition: first sentence of Wikipedia: Electroreception and electrogenesis (CC BY-SA 4.0)
- Elongation factor
- Elongation factors are a set of proteins that function at the ribosome, during protein synthesis, to facilitate translational elongation from the formation of the first to the last peptide bond of a growing polypeptide. Also: elongation. Definition: first sentence of Wikipedia: Elongation factor (CC BY-SA 4.0)
- Embryo
- An embryo is the initial stage of development for a multicellular organism. Also: embryos. Definition: first sentence of Wikipedia: Embryo (CC BY-SA 4.0)
- Embryonic stem cell
- Embryonic stem cells (ESCs) are pluripotent stem cells derived from the inner cell mass of a blastocyst, an early-stage pre-implantation embryo. Also: embryonic stem cells. Definition: first sentence of Wikipedia: Embryonic stem cell (CC BY-SA 4.0)
- Endemism
- Endemism is the state of a species being found only in a singular defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsewhere. Also: endemic. Definition: first sentence of Wikipedia: Endemism (CC BY-SA 4.0)
- Endoderm
- Endoderm is the innermost of the three primary germ layers in the very early embryo. Definition: first sentence of Wikipedia: Endoderm (CC BY-SA 4.0)
- Endogeny (biology)
- Endogeny, in biology, refers to the property of originating or developing from within an organism, tissue, or cell. Also: endogenous, endogenously. Definition: first sentence of Wikipedia: Endogeny (biology) (CC BY-SA 4.0)
- Endosome
- Endosomes are a collection of intracellular sorting organelles in eukaryotic cells. Also: endosomes. Definition: first sentence of Wikipedia: Endosome (CC BY-SA 4.0)
- Endosymbiont
- An endosymbiont or endobiont is an organism that lives within the body or cells of another organism. Also: endosymbiotic. Definition: first sentence of Wikipedia: Endosymbiont (CC BY-SA 4.0)
- Energy density
- In physics, energy density is the quotient between the amount of energy stored in a given system or contained in a given region of space and the volume of the system or region considered. Definition: first sentence of Wikipedia: Energy density (CC BY-SA 4.0)
- Entropy
- Entropy is a thermodynamic state variable that quantifies the probabilistic distribution of accessible microstates in a system. Definition: first sentence of Wikipedia: Entropy (CC BY-SA 4.0)
- Enzyme
- An enzyme is a biological macromolecule, usually a protein, that acts as a biological catalyst, accelerating chemical reactions without being consumed in the process. Also: enzymes. Definition: first sentence of Wikipedia: Enzyme (CC BY-SA 4.0)
- Eosinophil
- Eosinophils, sometimes called eosinophiles or, less commonly, acidophils, are a variety of white blood cells and one of the immune system components responsible for combating multicellular parasites and certain infections in vertebrates. Also: eosinophils. Definition: first sentence of Wikipedia: Eosinophil (CC BY-SA 4.0)
- Eosinophilic
- Greek suffix -phil, meaning loving) describes the staining of tissues, cells, or organelles after they have been washed with eosin, a dye commonly used in histological staining. Definition: first sentence of Wikipedia: Eosinophilic (CC BY-SA 4.0)
- Epicuticular wax
- Epicuticular wax is a waxy coating which covers the outer surface of the plant cuticle in land plants. Definition: first sentence of Wikipedia: Epicuticular wax (CC BY-SA 4.0)
- Epidermal growth factor
- Epidermal growth factor (EGF) is a protein that stimulates cell growth and differentiation by binding to its receptor, EGFR. Definition: first sentence of Wikipedia: Epidermal growth factor (CC BY-SA 4.0)
- Epidermis
- The epidermis is the outermost of the three major layers that constitute the skin, the inner layers being the dermis and hypodermis. Definition: first sentence of Wikipedia: Epidermis (CC BY-SA 4.0)
- Erythrocyte deformability
- In hematology, erythrocyte deformability refers to the ability of erythrocytes (red blood cells, RBCs) to change shape under a given level of applied stress without hemolysing (rupturing). Also: deformability. Definition: first sentence of Wikipedia: Erythrocyte deformability (CC BY-SA 4.0)
- Essential amino acid
- An essential amino acid, or indispensable amino acid, is an amino acid that cannot be synthesized from scratch by the organism fast enough to supply its demand, and must therefore come from the diet. Definition: first sentence of Wikipedia: Essential amino acid (CC BY-SA 4.0)
- Essential fatty acid
- Essential fatty acids are needed for various cellular metabolic processes and for the maintenance and function of tissues and organs. Also: essential. Definition: first sentence of Wikipedia: Essential fatty acid (CC BY-SA 4.0)
- Estrane
- Estrane is a C18 steroid derivative, with a gonane core. Definition: first sentence of Wikipedia: Estrane (CC BY-SA 4.0)
- Estrous cycle
- The estrous cycle (US-EN;) or oestrous cycle (UK-EN;) is a set of recurring physiological changes induced by reproductive hormones in females of mammalian subclass Theria. Also: estrous. Definition: first sentence of Wikipedia: Estrous cycle (CC BY-SA 4.0)
- Estuary
- An estuary is a partially enclosed coastal body of brackish water where freshwater from rivers or streams meets and mixes with saltwater from the open sea. Also: estuaries. Definition: first sentence of Wikipedia: Estuary (CC BY-SA 4.0)
- Ethanol
- Ethanol (also called ethyl alcohol, grain alcohol, drinking alcohol, or simply alcohol) is an organic compound with the chemical formula. Definition: first sentence of Wikipedia: Ethanol (CC BY-SA 4.0)
- Ethanolamine
- Ethanolamine (2-aminoethanol, monoethanolamine, ETA, or MEA) is a naturally occurring organic chemical compound with the formula or. Definition: first sentence of Wikipedia: Ethanolamine (CC BY-SA 4.0)
- Evolution
- Evolution is the change in the heritable characteristics of biological populations over successive generations. Also: evolutionary. Definition: first sentence of Wikipedia: Evolution (CC BY-SA 4.0)
- Evolutionary biology
- Evolutionary biology is a subfield of biology that analyzes the four mechanisms of evolution: natural selection, mutation, genetic drift, and gene flow. Definition: first sentence of Wikipedia: Evolutionary biology (CC BY-SA 4.0)
- Exotoxin
- An exotoxin is a toxin secreted by bacteria. Also: exotoxins. Definition: first sentence of Wikipedia: Exotoxin (CC BY-SA 4.0)
- Extracellular fluid
- In cell biology, extracellular fluid (ECF) denotes all body fluid outside the cells of any multicellular organism. Also: extracellular fluids. Definition: first sentence of Wikipedia: Extracellular fluid (CC BY-SA 4.0)
- Extracellular matrix
- In biology, the extracellular matrix (ECM), also called the intercellular matrix, is a network consisting of extracellular macromolecules and minerals, such as collagen, enzymes, glycoproteins and hydroxyapatite that provide structural and biochemical support to surrounding cells. Definition: first sentence of Wikipedia: Extracellular matrix (CC BY-SA 4.0)
- Extracellular space
- Extracellular space refers to the part of a multicellular organism outside the cells, usually taken to be outside the plasma membranes, and occupied by fluid. Definition: first sentence of Wikipedia: Extracellular space (CC BY-SA 4.0)
F
- Facilitated diffusion
- Facilitated diffusion (also known as facilitated transport or passive-mediated transport) is the process of spontaneous passive transport (as opposed to active transport) of molecules or ions across a biological membrane via specific transmembrane integral proteins. Definition: first sentence of Wikipedia: Facilitated diffusion (CC BY-SA 4.0)
- Fatty acid
- In chemistry, particularly in biochemistry, a fatty acid is a carboxylic acid with an aliphatic chain, which is either saturated or unsaturated. Definition: first sentence of Wikipedia: Fatty acid (CC BY-SA 4.0)
- Fatty acid desaturase
- Fatty acid desaturases (also called unsaturases) are a family of enzymes that convert saturated fatty acids into unsaturated fatty acids and polyunsaturated fatty acids. Also: desaturation. Definition: first sentence of Wikipedia: Fatty acid desaturase (CC BY-SA 4.0)
- Fatty acid metabolism
- Fatty acid metabolism consists of various metabolic processes involving or closely related to fatty acids, a family of molecules classified within the lipid macronutrient category. Definition: first sentence of Wikipedia: Fatty acid metabolism (CC BY-SA 4.0)
- Feminizing hormone therapy
- Feminizing hormone therapy, also known as transfeminine hormone therapy, is a form of gender-affirming care and a gender-affirming hormone therapy to change the primary and secondary sex characteristics of transgender people from masculine to feminine. Definition: first sentence of Wikipedia: Feminizing hormone therapy (CC BY-SA 4.0)
- Fetus
- A fetus or foetus is the unborn offspring of a viviparous animal that develops from an embryo. Definition: first sentence of Wikipedia: Fetus (CC BY-SA 4.0)
- Fibril
- Fibrils are structural biological materials found in nearly all living organisms. Also: fibrils. Definition: first sentence of Wikipedia: Fibril (CC BY-SA 4.0)
- Fibrillarin
- rRNA 2'-O-methyltransferase fibrillarin is an enzyme that in humans is encoded by the FBL gene. Definition: first sentence of Wikipedia: Fibrillarin (CC BY-SA 4.0)
- Fibronectin
- Fibronectin is a high-molecular weight (~500-~600 kDa) glycoprotein of the extracellular matrix that binds to membrane-spanning receptor proteins called integrins. Definition: first sentence of Wikipedia: Fibronectin (CC BY-SA 4.0)
- Fishery
- Fishery can mean either the enterprise of raising or harvesting fish and other aquatic life or, more commonly, the site where such enterprise takes place (a.k.a., fishing grounds). Also: fisheries. Definition: first sentence of Wikipedia: Fishery (CC BY-SA 4.0)
- Flagellum
- A flagellum (Latin for 'whip' or 'scourge') is a hair-like appendage that protrudes from certain plant and animal sperm cells, from fungal spores (zoospores), and from a wide range of microorganisms to provide motility. Also: flagella. Definition: first sentence of Wikipedia: Flagellum (CC BY-SA 4.0)
- Flower
- Flowers, also known as blossoms and blooms, are the reproductive structures of flowering plants. Also: flowering. Definition: first sentence of Wikipedia: Flower (CC BY-SA 4.0)
- Folliculogenesis
- In biology, folliculogenesis is the maturation of the ovarian follicle, a densely packed shell of somatic cells that contains an immature oocyte. Also: primordial follicle. Definition: first sentence of Wikipedia: Folliculogenesis (CC BY-SA 4.0)
- Fossil
- A fossil (from Classical Latin) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Definition: first sentence of Wikipedia: Fossil (CC BY-SA 4.0)
- Free agent
- In professional sports, a free agent is a player or manager who is eligible to sign with other clubs or franchises; i.e., not under contract to any specific team. Also: unrestricted free agent. Definition: first sentence of Wikipedia: Free agent (CC BY-SA 4.0)
- Fructose
- Fructose, or fruit sugar, is a common monosaccharide, i.e. a simple sugar. Definition: first sentence of Wikipedia: Fructose (CC BY-SA 4.0)
- Functional group
- In organic chemistry, a functional group is any substituent or moiety in a molecule that causes the molecule's characteristic chemical reactions. Also: chemical groups, functional groups. Definition: first sentence of Wikipedia: Functional group (CC BY-SA 4.0)
G
- Galactolipid
- Galactolipids are a type of glycolipid whose sugar group is galactose. Also: galactolipids. Definition: first sentence of Wikipedia: Galactolipid (CC BY-SA 4.0)
- Galactose
- Galactose is a common monosaccharide, i.e. a simple sugar. Definition: first sentence of Wikipedia: Galactose (CC BY-SA 4.0)
- Gametangium
- A gametangium is a sex organ or cell in which gametes are produced that is found in many multicellular protists, algae, fungi, and the gametophytes of plants. Definition: first sentence of Wikipedia: Gametangium (CC BY-SA 4.0)
- Gamete
- A gamete, reproductive cell, or sex cell, is a haploid cell that fuses with another haploid cell during fertilization in organisms that reproduce sexually. Definition: first sentence of Wikipedia: Gamete (CC BY-SA 4.0)
- Gametocyte
- A gametocyte is a eukaryotic germ cell that divides by mitosis into other gametocytes or by meiosis into gametids during gametogenesis. Definition: first sentence of Wikipedia: Gametocyte (CC BY-SA 4.0)
- Gas exchange
- Gas exchange is the physiological process by which gases move passively by diffusion across a surface. Definition: first sentence of Wikipedia: Gas exchange (CC BY-SA 4.0)
- Gastrulation
- Gastrulation is the stage in the early embryonic development of most animals, during which the blastula (a single-layered hollow sphere of cells), or in mammals, the blastocyst, is reorganized into a two-layered or three-layered embryo known as the gastrula, with an infold named the blastopore. Definition: first sentence of Wikipedia: Gastrulation (CC BY-SA 4.0)
- Gel
- A gel is a semi-solid that can have properties ranging from soft and weak to hard and tough. Also: colloidal gel. Definition: first sentence of Wikipedia: Gel (CC BY-SA 4.0)
- Gene silencing
- Gene silencing is the regulation of gene expression in a cell to prevent the expression of a certain gene. Definition: first sentence of Wikipedia: Gene silencing (CC BY-SA 4.0)
- Gene therapy
- Gene therapy is medical technology that aims to produce a therapeutic effect through the manipulation of gene expression or through altering the biological properties of living cells. Definition: first sentence of Wikipedia: Gene therapy (CC BY-SA 4.0)
- General transcription factor
- General transcription factors (GTFs), also known as basal transcriptional factors, are a class of protein transcription factors that bind to specific sites (promoter) on DNA to activate transcription of genetic information from DNA to messenger RNA. Also: general transcription factors. Definition: first sentence of Wikipedia: General transcription factor (CC BY-SA 4.0)
- Genetic code
- Genetic code is a set of rules used by living cells to translate information encoded within genetic material (DNA or RNA sequences of nucleotide triplets or codons) into proteins. Also: codon, codons, encoded. Definition: first sentence of Wikipedia: Genetic code (CC BY-SA 4.0)
- Genetic transformation
- In molecular biology and genetics, transformation is the genetic alteration of a bacterial cell resulting from the direct uptake and incorporation of exogenous genetic material from its surroundings through the cell membrane(s). Also: transformation. Definition: first sentence of Wikipedia: Genetic transformation (CC BY-SA 4.0)
- Genetics
- Genetics is the study of genes, genetic variation, and heredity in organisms. Definition: first sentence of Wikipedia: Genetics (CC BY-SA 4.0)
- Genome
- In the fields of molecular biology and genetics, a genome is all the genetic information of an organism. Also: genomes. Definition: first sentence of Wikipedia: Genome (CC BY-SA 4.0)
- Genus
- Genus is a taxonomic rank above species and below family as used in the biological classification of living and fossil organisms as well as viruses. Definition: first sentence of Wikipedia: Genus (CC BY-SA 4.0)
- Germ cell
- A germ cell is any cell that gives rise to the gametes of an organism that reproduces sexually. Definition: first sentence of Wikipedia: Germ cell (CC BY-SA 4.0)
- Germ layer
- A germ layer, primary germinal layer, or germinal layer is a primary layer of cells that forms during animal embryonic development. Also: germ layers. Definition: first sentence of Wikipedia: Germ layer (CC BY-SA 4.0)
- Germline
- In biology and genetics, the germline is the population of a multicellular organism's cells that develop into germ cells. Definition: first sentence of Wikipedia: Germline (CC BY-SA 4.0)
- Gestation
- Gestation is the period of development during the carrying of an embryo, and later fetus, inside viviparous animals (the embryo develops within the parent). Also: gestation period. Definition: first sentence of Wikipedia: Gestation (CC BY-SA 4.0)
- Gill slit
- Gill slits are individual openings to gills, i.e., multiple gill arches, which lack a single outer cover. Also: gill slits. Definition: first sentence of Wikipedia: Gill slit (CC BY-SA 4.0)
- Gillnetting
- Gillnetting is a fishing method that uses gillnets: vertical panels of netting that hang from a line with regularly spaced floaters that hold the line on the surface of the water. Also: gillnet, gillnets. Definition: first sentence of Wikipedia: Gillnetting (CC BY-SA 4.0)
- Gland
- A gland is a cell or an organ in an animal's body that produces and secretes different substances that the organism needs, either into the bloodstream or into a body cavity or outer surface. Definition: first sentence of Wikipedia: Gland (CC BY-SA 4.0)
- Glia
- Glia, also called glial cells or neuroglia, are non-neuronal cells in the central nervous system (the brain and the spinal cord) and in the peripheral nervous system that do not produce electrical impulses. Also: glial cells. Definition: first sentence of Wikipedia: Glia (CC BY-SA 4.0)
- Glucocorticoid
- Glucocorticoids (or, less commonly, glucocorticosteroids) are a class of corticosteroids, which are in turn a class of steroid hormones. Also: glucocorticoids. Definition: first sentence of Wikipedia: Glucocorticoid (CC BY-SA 4.0)
- Glucose
- Glucose is a sugar with the molecular formula. Definition: first sentence of Wikipedia: Glucose (CC BY-SA 4.0)
- Glutamate (neurotransmitter)
- Glutamate is an amino acid and a neurotransmitter (a chemical that nerve cells use to send signals to other cells). Also: glutamate. Definition: first sentence of Wikipedia: Glutamate (neurotransmitter) (CC BY-SA 4.0)
- Glutamic acid
- Glutamic acid (symbol Glu or E; known as glutamate in its anionic form), molecular formula, is an α-amino acid that is used by almost all organisms for the biosynthesis of proteins. Definition: first sentence of Wikipedia: Glutamic acid (CC BY-SA 4.0)
- Glycerol
- Glycerol is a sugar alcohol with chemical formula. Definition: first sentence of Wikipedia: Glycerol (CC BY-SA 4.0)
- Glycerophospholipid
- Glycerophospholipids or phosphoglycerides are glycerol-based phospholipids. Also: glycerophospholipids. Definition: first sentence of Wikipedia: Glycerophospholipid (CC BY-SA 4.0)
- Glycine
- Glycine (symbol Gly or G;) is an organic compound with the formula C2H5NO2, and is the simplest stable amino acid, distinguished by having a single hydrogen atom as its side chain. Definition: first sentence of Wikipedia: Glycine (CC BY-SA 4.0)
- Glycocalyx
- The glycocalyx, also known as the pericellular matrix and cell coat, is an external organelle consisting of a layer of glycosylated biomolecules called glycoconjugates, such as glycoproteins and glycolipids. Definition: first sentence of Wikipedia: Glycocalyx (CC BY-SA 4.0)
- Glycogen
- Glycogen is a multibranched polysaccharide of glucose that serves as a form of energy storage in animals, fungi, and bacteria. Definition: first sentence of Wikipedia: Glycogen (CC BY-SA 4.0)
- Glycosidic bond
- A glycosidic bond or glycosidic linkage is a type of ether bond that joins a carbohydrate (sugar) molecule to another group, which may or may not be another carbohydrate. Definition: first sentence of Wikipedia: Glycosidic bond (CC BY-SA 4.0)
- Glycosylation
- Glycosylation is the reaction in which a carbohydrate (or 'glycan'), i.e. a glycosyl donor, is attached to a hydroxyl or other functional group of another molecule (a glycosyl acceptor) in order to form a glycoconjugate. Definition: first sentence of Wikipedia: Glycosylation (CC BY-SA 4.0)
- Goaltender
- In ice hockey, the goaltender (commonly referred to as goalie or netminder) is the player responsible for preventing the hockey puck from entering their own team's net, thus preventing the opposing team from scoring. Definition: first sentence of Wikipedia: Goaltender (CC BY-SA 4.0)
- Gonad
- A gonad, sex gland, or reproductive organ is a mixed gland and sex organ that produces the gametes (reproductive cells), and sex hormones of an organism. Also: gonads. Definition: first sentence of Wikipedia: Gonad (CC BY-SA 4.0)
- Gonane
- Gonane (cyclopentanoperhydrophenanthrene) is a chemical compound with formula, whose structure consists of four hydrocarbon rings fused together: three cyclohexane units and one cyclopentane. Definition: first sentence of Wikipedia: Gonane (CC BY-SA 4.0)
- Gradient
- In vector calculus, the gradient of a scalar-valued differentiable function f of several variables is the vector field (or vector-valued function) \nabla f whose value at a point p gives the direction and the rate of fastest increase. Definition: first sentence of Wikipedia: Gradient (CC BY-SA 4.0)
- Granule (cell biology)
- In cell biology, a granule is a small particle barely visible by light microscopy. Also: granules. Definition: first sentence of Wikipedia: Granule (cell biology) (CC BY-SA 4.0)
- Granulocyte
- Granulocytes are cells in the innate immune system characterized by the presence of specific granules in their cytoplasm. Also: granulocytes. Definition: first sentence of Wikipedia: Granulocyte (CC BY-SA 4.0)
- Grape seed oil
- Grape seed oil (also called grapeseed oil or grape oil) is a vegetable oil derived from the seeds of grapes. Also: grape seeds. Definition: first sentence of Wikipedia: Grape seed oil (CC BY-SA 4.0)
- Groundwater
- Groundwater is the water present beneath Earth's surface in rock and soil pore spaces and in the fractures of rock formations. Definition: first sentence of Wikipedia: Groundwater (CC BY-SA 4.0)
- Growth factor
- A growth factor is a naturally occurring substance capable of stimulating cell proliferation, wound healing, and occasionally cellular differentiation. Also: growth factors. Definition: first sentence of Wikipedia: Growth factor (CC BY-SA 4.0)
- Growth hormone
- Growth hormone (GH) or somatotropin, also known as human growth hormone (hGH or HGH) in its human form, is a peptide hormone that stimulates growth, cell reproduction, and cell regeneration in humans and other animals. Definition: first sentence of Wikipedia: Growth hormone (CC BY-SA 4.0)
- Guanine
- Guanine (symbol G or Gua) is one of the four main nucleotide bases found in the nucleic acids DNA and RNA, the others being adenine, cytosine, and thymine (uracil in RNA). Definition: first sentence of Wikipedia: Guanine (CC BY-SA 4.0)
- Guanylyltransferase
- Guanylyl transferases are enzymes that transfer a guanosine mono phosphate group, usually from GTP to another molecule, releasing pyrophosphate. Also: guanosyl transferase. Definition: first sentence of Wikipedia: Guanylyltransferase (CC BY-SA 4.0)
H
- Half-life
- Half-life (symbol t) is the time required for a quantity (of substance) to reduce to half of its initial value. Definition: first sentence of Wikipedia: Half-life (CC BY-SA 4.0)
- Hat-trick
- A hat-trick or hat trick is the achievement of a generally positive feat three times in a match, or another achievement based on the number three. Also: hat trick. Definition: first sentence of Wikipedia: Hat-trick (CC BY-SA 4.0)
- Heart rate
- Heart rate is the frequency of the heartbeat measured by the number of contractions of the heart per minute (beats per minute or bpm). Definition: first sentence of Wikipedia: Heart rate (CC BY-SA 4.0)
- Hemodynamics
- Hemodynamics or haemodynamics are the dynamics of blood flow. Also: blood flow. Definition: first sentence of Wikipedia: Hemodynamics (CC BY-SA 4.0)
- Hemoglobin
- Hemoglobin (haemoglobin, Hb or Hgb) is a protein containing iron that facilitates the transportation of oxygen in red blood cells. Definition: first sentence of Wikipedia: Hemoglobin (CC BY-SA 4.0)
- Hemp oil
- Hemp oil (hemp seed oil) is oil obtained by pressing hemp seeds. Also: hempseed oil. Definition: first sentence of Wikipedia: Hemp oil (CC BY-SA 4.0)
- Heparin
- Heparin, also known as unfractionated heparin (UFH), is a medication and naturally occurring glycosaminoglycan. Definition: first sentence of Wikipedia: Heparin (CC BY-SA 4.0)
- Hepatocyte
- A hepatocyte is a cell of the main parenchymal tissue of the liver. Also: liver cell. Definition: first sentence of Wikipedia: Hepatocyte (CC BY-SA 4.0)
- Heptose
- A heptose is a monosaccharide with seven carbon atoms. Definition: first sentence of Wikipedia: Heptose (CC BY-SA 4.0)
- Herbivore
- A herbivore is an animal anatomically or physiologically evolved to feed on plants, especially upon vascular tissues such as foliage, fruits or seeds, as the main component of its diet. Definition: first sentence of Wikipedia: Herbivore (CC BY-SA 4.0)
- Heredity
- Heredity, also called inheritance or biological inheritance, is the passing on of traits from parents to their offspring; either through asexual reproduction or sexual reproduction, the offspring cells or organisms acquire the genetic information of their parents. Definition: first sentence of Wikipedia: Heredity (CC BY-SA 4.0)
- Hexose
- In chemistry, a hexose is a monosaccharide (simple sugar) with six carbon atoms. Definition: first sentence of Wikipedia: Hexose (CC BY-SA 4.0)
- Histamine
- Histamine or histamin is an organic nitrogenous compound found in mammals and many vegetables, fruits and food products. Definition: first sentence of Wikipedia: Histamine (CC BY-SA 4.0)
- Histiocyte
- A histiocyte is a vertebrate cell that is part of the mononuclear phagocyte system (also known as the reticuloendothelial system or lymphoreticular system). Also: histiocytes. Definition: first sentence of Wikipedia: Histiocyte (CC BY-SA 4.0)
- Histology
- Histology, also known as microscopic anatomy, microanatomy or histoanatomy, is the branch of biology that studies the microscopic anatomy of biological tissues. Definition: first sentence of Wikipedia: Histology (CC BY-SA 4.0)
- Histone
- In biology, histones are highly-basic proteins abundant in lysine and arginine residues that are found in eukaryotic cell nuclei and in most Archaeal phyla. Also: histones. Definition: first sentence of Wikipedia: Histone (CC BY-SA 4.0)
- Histopathology
- Histopathology (compound of three Greek words: ἱστός histos 'tissue', πάθος pathos 'suffering', and -λογία -logia 'study of') is the microscopic examination of tissue in order to study the manifestations of disease. Definition: first sentence of Wikipedia: Histopathology (CC BY-SA 4.0)
- Holotype
- A holotype is a single physical example (or illustration) of an organism that is the one that was used when the species (or lower-ranked taxon) was formally described. Definition: first sentence of Wikipedia: Holotype (CC BY-SA 4.0)
- Homogeneity and heterogeneity
- Homogeneity and heterogeneity are concepts relating to the uniformity of a substance, process or image. Also: homogeneous. Definition: first sentence of Wikipedia: Homogeneity and heterogeneity (CC BY-SA 4.0)
- Hormone
- A hormone is a class of signaling molecules in multicellular organisms that are sent to distant organs or tissues by complex biological processes to regulate physiology and behavior. Also: hormones. Definition: first sentence of Wikipedia: Hormone (CC BY-SA 4.0)
- Hormone receptor
- A hormone receptor is a receptor molecule that binds to a specific hormone. Also: hormone receptors. Definition: first sentence of Wikipedia: Hormone receptor (CC BY-SA 4.0)
- Hormone replacement therapy
- Hormone replacement therapy (HRT), also known as menopausal hormone therapy or postmenopausal hormone therapy, is a form of hormone therapy used to treat symptoms associated with female menopause. Definition: first sentence of Wikipedia: Hormone replacement therapy (CC BY-SA 4.0)
- Humus
- Humus is the stable form of soil organic matter derived from decomposition of plant and animal substances. Definition: first sentence of Wikipedia: Humus (CC BY-SA 4.0)
- Hyaluronic acid
- Hyaluronic acid, also called hyaluronan, is an anionic, nonsulfated glycosaminoglycan distributed widely throughout connective, epithelial, and neural tissues. Also: hyaluronan. Definition: first sentence of Wikipedia: Hyaluronic acid (CC BY-SA 4.0)
- Hydrogen
- Hydrogen is a chemical element; it has the symbolH and atomic number1. Definition: first sentence of Wikipedia: Hydrogen (CC BY-SA 4.0)
- Hydrolase
- In biochemistry, hydrolases constitute a class of enzymes that commonly function as biochemical catalysts that use water to break a chemical bond: Also: hydrolases. Definition: first sentence of Wikipedia: Hydrolase (CC BY-SA 4.0)
- Hydrolysis
- Hydrolysis is any chemical reaction in which a molecule of water breaks one or more chemical bonds. Definition: first sentence of Wikipedia: Hydrolysis (CC BY-SA 4.0)
- Hydrophile
- A hydrophile is a molecule or other molecular entity that is attracted to water molecules and tends to be dissolved by water. Also: hydrophilic. Definition: first sentence of Wikipedia: Hydrophile (CC BY-SA 4.0)
- Hydrophobe
- In chemistry, hydrophobicity is the chemical property of a molecule (called a hydrophobe) that is seemingly repelled from a mass of water. Also: hydrophobic, hydrophobicity. Definition: first sentence of Wikipedia: Hydrophobe (CC BY-SA 4.0)
- Hydroxy group
- In chemistry, a hydroxy or hydroxyl group is a functional group with the chemical formula and composed of one oxygen atom covalently bonded to one hydrogen atom. Also: hydroxyl. Definition: first sentence of Wikipedia: Hydroxy group (CC BY-SA 4.0)
- Hydroxylation
- In chemistry, hydroxylation refers to the installation of a hydroxyl group into an organic compound. Definition: first sentence of Wikipedia: Hydroxylation (CC BY-SA 4.0)
- Hyperpolarization (biology)
- Hyperpolarization is a change in a cell's membrane potential that makes it more negative. Also: hyperpolarization. Definition: first sentence of Wikipedia: Hyperpolarization (biology) (CC BY-SA 4.0)
I
- Ichthyology
- Ichthyology is the branch of zoology devoted to the study of fish, including bony fish (Osteichthyes), cartilaginous fish (Chondrichthyes), and jawless fish (Agnatha). Also: ichthyologist. Definition: first sentence of Wikipedia: Ichthyology (CC BY-SA 4.0)
- Immune system
- The immune system is a network of biological systems that protects an organism from diseases. Also: immune. Definition: first sentence of Wikipedia: Immune system (CC BY-SA 4.0)
- Immunofluorescence
- Immunofluorescence (IF) is a light microscopy-based technique that allows detection and localization of a wide variety of target biomolecules within a cell or tissue at a quantitative level. Definition: first sentence of Wikipedia: Immunofluorescence (CC BY-SA 4.0)
- Immunological memory
- Immunological memory is the ability of the immune system to quickly and specifically recognize an antigen that the body has previously encountered and initiate a corresponding immune response. Definition: first sentence of Wikipedia: Immunological memory (CC BY-SA 4.0)
- In vivo
- Studies that are in vivo (Latin for "within the living"; often not italicized in English) are those in which the effects of various biological entities are tested on whole, living organisms or cells, usually animals, including humans, and plants, as opposed to a tissue extract or dead organism. Definition: first sentence of Wikipedia: In vivo (CC BY-SA 4.0)
- Indel
- Indel (insertion-deletion) is a molecular biology term for an insertion or deletion of bases in the genome of an organism. Also: deletion. Definition: first sentence of Wikipedia: Indel (CC BY-SA 4.0)
- Initiation factor
- In molecular biology, initiation factors are proteins that bind to the small subunit of the ribosome during the initiation of translation, a part of protein biosynthesis. Also: initiation factors. Definition: first sentence of Wikipedia: Initiation factor (CC BY-SA 4.0)
- Innate immune system
- The innate immune system or nonspecific immune system is one of the two main immunity strategies in vertebrates (the other being the adaptive immune system). Definition: first sentence of Wikipedia: Innate immune system (CC BY-SA 4.0)
- Innate lymphoid cell
- Innate lymphoid cells (ILCs) are the most recently discovered family of innate immune cells, derived from common lymphoid progenitors (CLPs). Also: innate lymphoid cells. Definition: first sentence of Wikipedia: Innate lymphoid cell (CC BY-SA 4.0)
- Inner cell mass
- The inner cell mass (ICM) or embryoblast (known as the pluriblast in marsupials) is a structure in the early development of a mammalian embryo. Definition: first sentence of Wikipedia: Inner cell mass (CC BY-SA 4.0)
- Inner mitochondrial membrane
- The inner mitochondrial membrane (IMM) is the mitochondrial membrane which separates the mitochondrial matrix from the intermembrane space. Also: inner membrane. Definition: first sentence of Wikipedia: Inner mitochondrial membrane (CC BY-SA 4.0)
- Insect
- Insects (from Latin insectum) are invertebrates of the class Insecta. Also: insects. Definition: first sentence of Wikipedia: Insect (CC BY-SA 4.0)
- Insecticide
- Insecticides are pesticides used to kill insects. Also: insecticides. Definition: first sentence of Wikipedia: Insecticide (CC BY-SA 4.0)
- Insulator (electricity)
- An electrical insulator is a material in which electric current does not flow freely. Also: insulate. Definition: first sentence of Wikipedia: Insulator (electricity) (CC BY-SA 4.0)
- Insulator (genetics)
- An insulator is a type of cis-regulatory element known as a long-range regulatory element. Also: insulators. Definition: first sentence of Wikipedia: Insulator (genetics) (CC BY-SA 4.0)
- Insulin
- Insulin is a peptide hormone produced by beta cells of the pancreatic islets encoded in humans by the insulin (INS) gene. Definition: first sentence of Wikipedia: Insulin (CC BY-SA 4.0)
- Integral membrane protein
- An integral, or intrinsic, membrane protein (IMP) is a type of membrane protein that is permanently attached to the biological membrane. Also: integral membrane proteins. Definition: first sentence of Wikipedia: Integral membrane protein (CC BY-SA 4.0)
- Integrin
- Integrins are transmembrane receptors that help cell–cell and cell–extracellular matrix (ECM) adhesion. Also: integrins. Definition: first sentence of Wikipedia: Integrin (CC BY-SA 4.0)
- Interdisciplinarity
- Interdisciplinarity, also known as interdisciplinary studies, is the combination of multiple academic disciplines into one activity (e.g., a research project). Also: multi-disciplinary. Definition: first sentence of Wikipedia: Interdisciplinarity (CC BY-SA 4.0)
- Interferon gamma
- Interferon gamma (IFN-γ) is a family of dimerized soluble cytokines in the type II class of interferons. Definition: first sentence of Wikipedia: Interferon gamma (CC BY-SA 4.0)
- Intermediate filament
- Intermediate filaments (IFs) are cytoskeletal structural components found in the cells of vertebrates, and many invertebrates. Also: intermediate filaments. Definition: first sentence of Wikipedia: Intermediate filament (CC BY-SA 4.0)
- Intermembrane space
- An intermembrane space refers to the region of space which occurs between two or more adjacent plasma membranes within a given cellular organelle. Definition: first sentence of Wikipedia: Intermembrane space (CC BY-SA 4.0)
- International nonproprietary name
- INNs are intended to make communication more precise by providing a unique standard name for each active ingredient, to avoid prescribing errors. Definition: first sentence of Wikipedia: International nonproprietary name (CC BY-SA 4.0)
- International Union for Conservation of Nature
- The International Union for Conservation of Nature (IUCN) is an international organization working in the field of nature conservation and sustainable use of natural resources. Also: iucn. Definition: first sentence of Wikipedia: International Union for Conservation of Nature (CC BY-SA 4.0)
- Internodal segment
- In neuroscience, an internodal segment (or internode) is the portion of a nerve fiber between two nodes of Ranvier. Definition: first sentence of Wikipedia: Internodal segment (CC BY-SA 4.0)
- Intertidal zone
- The intertidal zone, or foreshore, is the area above water level at low tide and underwater at high tide; in other words, it is the part of the littoral zone within the tidal range. Also: intertidal. Definition: first sentence of Wikipedia: Intertidal zone (CC BY-SA 4.0)
- Intracellular transport
- Intracellular transport is the movement of vesicles and substances within a cell. Definition: first sentence of Wikipedia: Intracellular transport (CC BY-SA 4.0)
- Intron
- An intron is any nucleotide sequence within a gene that is not expressed or operative in the final RNA product. Also: introns. Definition: first sentence of Wikipedia: Intron (CC BY-SA 4.0)
- Invertebrate
- Invertebrates are animals that neither develop nor retain a vertebral column (commonly known as a spine or backbone), which evolved from the notochord. Also: invertebrates. Definition: first sentence of Wikipedia: Invertebrate (CC BY-SA 4.0)
- Ion channel
- Ion channels are pore-forming membrane proteins that allow ions to pass through the channel pore. Also: ion channels. Definition: first sentence of Wikipedia: Ion channel (CC BY-SA 4.0)
- Iron sights
- Iron sights are a system of physical alignment markers used as a sighting device to assist the accurate aiming of ranged weapons such as firearms, airguns, crossbows, and bows, or less commonly as a primitive finder sight for optical telescopes. Definition: first sentence of Wikipedia: Iron sights (CC BY-SA 4.0)
- Isoform
- In genetics, an isoform is a member of a set of similar products that originate from the same gene; such a set can consist of mRNAs or their resultant proteins. Also: isoforms. Definition: first sentence of Wikipedia: Isoform (CC BY-SA 4.0)
- Isoleucine
- Isoleucine (symbol Ile or I) is an α-amino acid that is used in the biosynthesis of proteins. Definition: first sentence of Wikipedia: Isoleucine (CC BY-SA 4.0)
- Isoprene
- Isoprene, or 2-methyl-1,3-butadiene, is a common volatile organic compound with the formula CH2=C(CH3)−CH=CH2. Definition: first sentence of Wikipedia: Isoprene (CC BY-SA 4.0)
K
- Ketone
- In organic chemistry, a ketone is an organic compound with the structure, where R and R' can be a variety of carbon-containing substituents. Also: ketones. Definition: first sentence of Wikipedia: Ketone (CC BY-SA 4.0)
- Kinesin
- A kinesin is a protein complex belonging to a class of motor proteins found in eukaryotic cells. Definition: first sentence of Wikipedia: Kinesin (CC BY-SA 4.0)
- Kleptoplasty
- Kleptoplasty or kleptoplastidy is a process in symbiotic relationships whereby plastids, notably chloroplasts from algae, are sequestered by the host. Definition: first sentence of Wikipedia: Kleptoplasty (CC BY-SA 4.0)
L
- Lamin
- Lamins, also known as nuclear lamins, are fibrous proteins in type V intermediate filaments, providing structural function and transcriptional regulation in the cell nucleus. Also: lamins. Definition: first sentence of Wikipedia: Lamin (CC BY-SA 4.0)
- Laminopathy
- Laminopathies (lamino- + -pathy) are a group of rare genetic disorders caused by mutations in genes encoding proteins of the nuclear lamina. Also: laminopathies. Definition: first sentence of Wikipedia: Laminopathy (CC BY-SA 4.0)
- Lanosterol
- Lanosterol is a tetracyclic triterpenoid from which all animal and fungal steroids are derived. Definition: first sentence of Wikipedia: Lanosterol (CC BY-SA 4.0)
- Lateral line
- The lateral line, also called the lateral line organ, is a system of sensory organs found in fish, used to detect movement, vibration, and pressure gradients in the surrounding water. Definition: first sentence of Wikipedia: Lateral line (CC BY-SA 4.0)
- Leucine
- Leucine or leucin (symbol Leu or L) is an essential amino acid that is used in the biosynthesis of proteins. Definition: first sentence of Wikipedia: Leucine (CC BY-SA 4.0)
- Leucoplast
- Leucoplasts ("formed, molded") are a category of plastid and as such are organelles found in plant cells. Also: leucoplasts. Definition: first sentence of Wikipedia: Leucoplast (CC BY-SA 4.0)
- Ligand
- In coordination chemistry, a ligand is an ion or molecule with a functional group that binds to a central metal atom to form a coordination complex. Definition: first sentence of Wikipedia: Ligand (CC BY-SA 4.0)
- Light
- Light, visible light, or visible radiation is electromagnetic radiation that can be perceived by the human eye. Definition: first sentence of Wikipedia: Light (CC BY-SA 4.0)
- Lignin
- Lignin is a class of complex organic polymers that form key structural materials in the support tissues of most plants. Definition: first sentence of Wikipedia: Lignin (CC BY-SA 4.0)
- Linoleic acid
- Linoleic acid (LA) is an organic compound with the formula. Definition: first sentence of Wikipedia: Linoleic acid (CC BY-SA 4.0)
- Linseed oil
- Linseed oil, also known as flaxseed oil or flax oil (in its edible form), is a colorless to yellowish oil obtained from the dried, ripened seeds of the flax plant (Linum usitatissimum). Also: flaxseeds. Definition: first sentence of Wikipedia: Linseed oil (CC BY-SA 4.0)
- Lipid metabolism
- Lipid metabolism is the synthesis and degradation of lipids in cells, involving the breakdown and storage of fats for energy and the synthesis of structural and functional lipids, such as those involved in the construction of cell membranes. Definition: first sentence of Wikipedia: Lipid metabolism (CC BY-SA 4.0)
- Lipid signaling
- Lipid signaling, broadly defined, refers to any biological cell signaling event involving a lipid messenger that binds a protein target, such as a receptor, kinase or phosphatase, which in turn mediate the effects of these lipids on specific cellular responses. Also: signaling. Definition: first sentence of Wikipedia: Lipid signaling (CC BY-SA 4.0)
- Lipid-anchored protein
- Lipid-anchored proteins (also known as lipid-linked proteins) are proteins that are covalently attached to lipids embedded into biological membranes. Also: lipidation. Definition: first sentence of Wikipedia: Lipid-anchored protein (CC BY-SA 4.0)
- Lipophilicity
- Lipophilicity (from Greek λίπος "fat" and φίλος "friendly") is the ability of a chemical compound to dissolve in fats, oils, lipids, and non-polar solvents such as hexane or toluene. Also: lipophilic. Definition: first sentence of Wikipedia: Lipophilicity (CC BY-SA 4.0)
- Liver
- The liver is a major metabolic organ exclusively found in vertebrates which performs many essential biological functions, such as detoxification of the organism and the synthesis of various proteins and various other biochemicals necessary for digestion and growth. Definition: first sentence of Wikipedia: Liver (CC BY-SA 4.0)
- Lockout (sports)
- In North American professional sports, a lockout is the shutdown of a professional sports league by team owners, usually due to a failure of a sports league to come to agree on a collective bargaining agreement with the league's player union. Also: lockout. Definition: first sentence of Wikipedia: Lockout (sports) (CC BY-SA 4.0)
- Locus coeruleus
- The locus coeruleus (LC), also spelled locus caeruleus or locus ceruleus, is a nucleus in the pons of the brainstem involved with physiological responses to stress and panic. Definition: first sentence of Wikipedia: Locus coeruleus (CC BY-SA 4.0)
- Longline fishing
- Longline fishing, or longlining, is a commercial fishing angling technique that uses a long main line with baited hooks attached at intervals via short branch lines called snoods or gangions. Also: longline. Definition: first sentence of Wikipedia: Longline fishing (CC BY-SA 4.0)
- Lumen (anatomy)
- In biology, a lumen is the inside space of a tubular structure, such as an artery or intestine. Also: lumen. Definition: first sentence of Wikipedia: Lumen (anatomy) (CC BY-SA 4.0)
- Lung
- The lungs are the primary organs of the respiratory system in many animals, including humans. Also: lungs. Definition: first sentence of Wikipedia: Lung (CC BY-SA 4.0)
- Lymphatic system
- The lymphatic system, or lymphoid system, is an organ system in vertebrates that is part of the immune system and complementary to the circulatory system. Definition: first sentence of Wikipedia: Lymphatic system (CC BY-SA 4.0)
- Lymphocyte
- A lymphocyte is a type of white blood cell (leukocyte) in the immune system of most vertebrates. Also: lymphocytes. Definition: first sentence of Wikipedia: Lymphocyte (CC BY-SA 4.0)
- Lymphoma
- Lymphoma is a group of blood and lymph tumors that develop from lymphocytes (a type of white blood cell). Definition: first sentence of Wikipedia: Lymphoma (CC BY-SA 4.0)
- Lysis
- Lysis is the breaking down of the membrane of a cell, often by viral, enzymic, or osmotic (that is, "lytic") mechanisms that compromise its integrity. Definition: first sentence of Wikipedia: Lysis (CC BY-SA 4.0)
- Lysozyme
- Lysozyme is an antimicrobial enzyme produced by animals that forms part of the innate immune system. Also: lysozymes. Definition: first sentence of Wikipedia: Lysozyme (CC BY-SA 4.0)
M
- Magazine (firearms)
- A magazine is an ammunition storage and feeding device for a repeating firearm, either integral with the gun (internal or fixed external) or detachable. Also: box magazine. Definition: first sentence of Wikipedia: Magazine (firearms) (CC BY-SA 4.0)
- Mammal
- A mammal is a vertebrate animal of the class Mammalia. Also: mammals. Definition: first sentence of Wikipedia: Mammal (CC BY-SA 4.0)
- Mangrove
- A mangrove is a shrub or tree that grows mainly in coastal saline or brackish water. Also: mangroves. Definition: first sentence of Wikipedia: Mangrove (CC BY-SA 4.0)
- Mass diffusivity
- Diffusivity, mass diffusivity or diffusion coefficient is usually written as the proportionality constant between the molar flux due to molecular diffusion and the negative value of the gradient in the concentration of the species. Also: diffusion coefficient. Definition: first sentence of Wikipedia: Mass diffusivity (CC BY-SA 4.0)
- Materials science
- Materials science is an interdisciplinary field concerned with understanding the relationships between the structure of materials and their properties and using this knowledge to design materials for specific applications. Definition: first sentence of Wikipedia: Materials science (CC BY-SA 4.0)
- Matter
- In physical science, matter is any substance that has mass and takes up space by having volume. Definition: first sentence of Wikipedia: Matter (CC BY-SA 4.0)
- Mediator (coactivator)
- Mediator is a multiprotein complex that functions as a transcriptional coactivator in all eukaryotes. Also: mediator complex. Definition: first sentence of Wikipedia: Mediator (coactivator) (CC BY-SA 4.0)
- Medical diagnosis
- Medical diagnosis (abbreviated as Dx, Dx, or Ds) is the process of determining which disease or condition explains a person's symptoms and signs. Definition: first sentence of Wikipedia: Medical diagnosis (CC BY-SA 4.0)
- Medicine
- Medicine is the science and practice of caring for patients, managing the diagnosis, prognosis, prevention, treatment and palliation of their injury or disease, while promoting their health. Definition: first sentence of Wikipedia: Medicine (CC BY-SA 4.0)
- Medroxyprogesterone acetate
- Medroxyprogesterone acetate (MPA), whose injectable form is known as depot medroxyprogesterone acetate (DMPA) and sold under the brand name Depo-Provera among others, is a hormonal medication of the progestin type. Definition: first sentence of Wikipedia: Medroxyprogesterone acetate (CC BY-SA 4.0)
- Meiosis
- Meiosis is a special type of cell division of germ cells in sexually-reproducing organisms that produces the gametes: the sperm or egg cells. Definition: first sentence of Wikipedia: Meiosis (CC BY-SA 4.0)
- Melanocyte
- Melanocytes are melanin-producing neural crest-derived cells located in the bottom layer (the stratum basale) of the skin's epidermis, the middle layer of the eye (the uvea), the inner ear, vaginal epithelium, meninges, bones, and heart found in many mammals and birds. Also: melanocytes. Definition: first sentence of Wikipedia: Melanocyte (CC BY-SA 4.0)
- Membrane progesterone receptor
- Membrane progesterone receptors (mPRs) are a group of cell surface receptors and membrane steroid receptors belonging to the progestin and adipoQ receptor (PAQR) family which bind the endogenous progestogen and neurosteroid progesterone, as well as the neurosteroid allopregnanolone. Also: membrane progesterone receptors. Definition: first sentence of Wikipedia: Membrane progesterone receptor (CC BY-SA 4.0)
- Membrane transport protein
- A membrane transport protein is a membrane protein involved in the movement of ions, small molecules, and macromolecules such as another protein, across a biological membrane. Also: membrane transport proteins, transporters. Definition: first sentence of Wikipedia: Membrane transport protein (CC BY-SA 4.0)
- Mesoderm
- The mesoderm is the middle layer of the three germ layers that develops during gastrulation in the very early development of the embryo of most animals. Definition: first sentence of Wikipedia: Mesoderm (CC BY-SA 4.0)
- Metal-organic compound
- Metal-organic compounds (jargon: metalorganics, metallo-organics) are a class of chemical compounds that contain metals and organic ligands, but lacking direct metal-carbon bonds. Also: metalorganic. Definition: first sentence of Wikipedia: Metal-organic compound (CC BY-SA 4.0)
- Methyl group
- In organic chemistry, a methyl group is an alkyl derived from methane, containing one carbon atom bonded to three hydrogen atoms, having chemical formula (whereas normal methane has the formula). Also: methyl. Definition: first sentence of Wikipedia: Methyl group (CC BY-SA 4.0)
- Methylation
- Methylation, in the chemical sciences, is the addition of a methyl group on a substrate, or the substitution of an atom (or group) by a methyl group. Definition: first sentence of Wikipedia: Methylation (CC BY-SA 4.0)
- Microbody
- A microbody (or cytosome) is a type of organelle that is found in the cells of plants, protozoa, fungi, and animals. Definition: first sentence of Wikipedia: Microbody (CC BY-SA 4.0)
- Microcin
- Microcins are very small bacteriocins, composed of relatively few amino acids. Also: microcins. Definition: first sentence of Wikipedia: Microcin (CC BY-SA 4.0)
- Microglia
- Microglia are a type of glial cell located throughout the brain and spinal cord of the central nervous system (CNS). Definition: first sentence of Wikipedia: Microglia (CC BY-SA 4.0)
- Micrometre
- The micrometre (micrometer in US spelling; symbol: μm) is a unit of length in the International System of Units (SI) equalling e=-6 (SI standard prefix "micro-" = e=-6); that is, one millionth of a metre (or one thousandth of a millimetre, 0.001, or about 0.00004). Also: micrometres. Definition: first sentence of Wikipedia: Micrometre (CC BY-SA 4.0)
- Microorganism
- A microorganism, or microbe, is an organism of microscopic size, which may exist in its single-celled form or as a colony of cells. Also: microbes. Definition: first sentence of Wikipedia: Microorganism (CC BY-SA 4.0)
- Microscopy
- Microscopy is the technical field of using microscopes to view subjects too small to be seen with the naked eye (objects that are not within the resolution range of the normal eye). Definition: first sentence of Wikipedia: Microscopy (CC BY-SA 4.0)
- Microtome
- A microtome (from the Greek mikros, meaning "small", and temnein, meaning "to cut") is a cutting tool used to produce extremely thin slices of material known as sections, with the process being termed microsectioning. Also: frozen tissue-sections. Definition: first sentence of Wikipedia: Microtome (CC BY-SA 4.0)
- Microtubule nucleation
- In cell biology, microtubule nucleation is the process that initiates the formation of microtubules. Also: nucleated. Definition: first sentence of Wikipedia: Microtubule nucleation (CC BY-SA 4.0)
- Middle lamella
- The middle lamella is a layer that cements together the primary cell walls of two adjoining plant cells. Definition: first sentence of Wikipedia: Middle lamella (CC BY-SA 4.0)
- Mineralocorticoid
- Mineralocorticoids are a class of corticosteroids, which in turn are a class of steroid hormones. Also: mineralocorticoids. Definition: first sentence of Wikipedia: Mineralocorticoid (CC BY-SA 4.0)
- Mitochondrial disease
- Mitochondrial disease is a group of genetic disorders caused by mitochondrial dysfunction. Also: mitochondrial diseases. Definition: first sentence of Wikipedia: Mitochondrial disease (CC BY-SA 4.0)
- Mitochondrial DNA
- Mitochondrial DNA (mDNA or mtDNA) is the DNA located in the mitochondria organelles in a eukaryotic cell that converts chemical energy from organic compounds into adenosine triphosphate (ATP). Also: mitochondrial. Definition: first sentence of Wikipedia: Mitochondrial DNA (CC BY-SA 4.0)
- Mitochondrial matrix
- In a mitochondrion, the matrix is the space within the inner membrane. Also: matrix. Definition: first sentence of Wikipedia: Mitochondrial matrix (CC BY-SA 4.0)
- Mitosis
- Mitosis is a part of the cell cycle in eukaryotic cells in which replicated chromosomes are separated into two new nuclei. Definition: first sentence of Wikipedia: Mitosis (CC BY-SA 4.0)
- Mobilome
- The mobilome is the entire set of mobile genetic elements in a genome. Definition: first sentence of Wikipedia: Mobilome (CC BY-SA 4.0)
- Molecular binding
- Molecular binding is an attractive interaction between two molecules that results in a stable association in which the molecules are in close proximity to each other. Also: binding. Definition: first sentence of Wikipedia: Molecular binding (CC BY-SA 4.0)
- Molecular cloning
- Molecular cloning is a set of experimental methods in molecular biology that are used to assemble recombinant DNA molecules and to direct their replication within host organisms. Definition: first sentence of Wikipedia: Molecular cloning (CC BY-SA 4.0)
- Molecular mass
- The molecular mass (m) is the mass of a given molecule, often expressed in units of daltons (Da). Definition: first sentence of Wikipedia: Molecular mass (CC BY-SA 4.0)
- Molecular medicine
- Molecular medicine is a broad field, where physical, chemical, biological, bioinformatics and medical techniques are used to describe molecular structures and mechanisms, identify fundamental molecular and genetic errors of disease, and to develop molecular interventions to correct them. Definition: first sentence of Wikipedia: Molecular medicine (CC BY-SA 4.0)
- Molecule
- A molecule is a group of two or more atoms that are held together by attractive forces known as chemical bonds; depending on context, the term may or may not include ions that satisfy this criterion. Definition: first sentence of Wikipedia: Molecule (CC BY-SA 4.0)
- Mollusca
- Mollusca is a phylum of protostomic invertebrate animals, whose members are known as molluscs or mollusks. Also: mollusc, molluscs, mollusk, mollusks. Definition: first sentence of Wikipedia: Mollusca (CC BY-SA 4.0)
- Monoamine neurotransmitter
- Monoamine neurotransmitters are neurotransmitters and neuromodulators that contain one amino group connected to an aromatic ring by a two-carbon chain (such as -CH2-CH2-). Also: monoamines. Definition: first sentence of Wikipedia: Monoamine neurotransmitter (CC BY-SA 4.0)
- Monocyte
- Monocytes are a type of leukocyte or white blood cell. Also: monocytes. Definition: first sentence of Wikipedia: Monocyte (CC BY-SA 4.0)
- Monoglyceride
- Monoglycerides (also: acylglycerols or monoacylglycerols) are a class of glycerides which are composed of a molecule of glycerol linked to a fatty acid via an ester bond. Also: monoglycerides. Definition: first sentence of Wikipedia: Monoglyceride (CC BY-SA 4.0)
- Monomer
- A monomer is a molecule that can react together with other monomer molecules to form a larger polymer chain or two- or three-dimensional network in a process called polymerization. Also: monomers. Definition: first sentence of Wikipedia: Monomer (CC BY-SA 4.0)
- Mononuclear phagocyte system
- In immunology, the mononuclear phagocyte system or mononuclear phagocytic system (MPS), also known as the macrophage system, is a part of the immune system that consists of the phagocytic cells located in reticular connective tissue. Definition: first sentence of Wikipedia: Mononuclear phagocyte system (CC BY-SA 4.0)
- Morphological derivation
- Morphological derivation, in linguistics, is the process of forming a new word from an existing word, often by adding a prefix or suffix, such as un- or -ness. Also: derives. Definition: first sentence of Wikipedia: Morphological derivation (CC BY-SA 4.0)
- Morphology (biology)
- In biology, morphology is the study of the form and structure of organisms and their specific structural features. Also: morphology. Definition: first sentence of Wikipedia: Morphology (biology) (CC BY-SA 4.0)
- Mortality rate
- Mortality rate, or death rate, is a measure of the number of deaths (in general, or due to a specific cause) in a particular population, scaled to the size of that population, per unit of time. Also: all-cause mortality. Definition: first sentence of Wikipedia: Mortality rate (CC BY-SA 4.0)
- Motor neuron
- A motor neuron (or motoneuron), also known as efferent neuron is a neuron that allows for both voluntary and involuntary movements of the body through muscles and glands. Definition: first sentence of Wikipedia: Motor neuron (CC BY-SA 4.0)
- Motor protein
- Motor proteins are a class of molecular motors that can move along the cytoskeleton of cells. Also: motor proteins. Definition: first sentence of Wikipedia: Motor protein (CC BY-SA 4.0)
- Movement protein
- A movement protein (MP) is a specific virus-encoded protein that is thought to be a general feature of plant genomes. Also: movement proteins. Definition: first sentence of Wikipedia: Movement protein (CC BY-SA 4.0)
- Mucous gland
- Mucous glands, also known as muciparous glands, are found in several different parts of the body, and they typically stain lighter than serous glands during standard histological preparation. Also: mucous glands. Definition: first sentence of Wikipedia: Mucous gland (CC BY-SA 4.0)
- Mucous membrane
- A mucous membrane or mucosa is a membrane that lines various cavities in the body of an organism and covers the surface of internal organs. Also: mucous membranes. Definition: first sentence of Wikipedia: Mucous membrane (CC BY-SA 4.0)
- Multicellular organism
- A multicellular organism is an organism that consists of more than one cell, and more than one cell type, unlike unicellular organisms. Also: multicellular. Definition: first sentence of Wikipedia: Multicellular organism (CC BY-SA 4.0)
- Muscle
- Muscle is a specialised soft tissue, one of the four basic types of animal tissues. Definition: first sentence of Wikipedia: Muscle (CC BY-SA 4.0)
- Muscle cell
- A muscle cell, also known as a myocyte, is a mature contractile cell in the muscle of an animal. Definition: first sentence of Wikipedia: Muscle cell (CC BY-SA 4.0)
- Muscle contraction
- Muscle contraction is the activation of tension-generating sites within muscle cells. Definition: first sentence of Wikipedia: Muscle contraction (CC BY-SA 4.0)
- Myofibril
- A myofibril (also known as a muscle fibril or sarcostyle) is a basic rod-like organelle of a muscle cell. Also: myofibrils. Definition: first sentence of Wikipedia: Myofibril (CC BY-SA 4.0)
- Myogenesis
- Myogenesis is the formation of skeletal muscular tissue, particularly during embryonic development. Definition: first sentence of Wikipedia: Myogenesis (CC BY-SA 4.0)
- Myosin head
- The myosin head is the part of the thick myofilament made up of myosin that acts in muscle contraction, by sliding over thin myofilaments of actin. Definition: first sentence of Wikipedia: Myosin head (CC BY-SA 4.0)
N
- Nanometre
- One nanometre can be expressed in scientific notation as 1 × 10−9 m and as m. Also: nanometer, nanometers. Definition: first sentence of Wikipedia: Nanometre (CC BY-SA 4.0)
- Nanoparticle
- A nanoparticle or ultrafine particle is a particle of matter 1 to 100 nanometres (nm) in diameter. Also: nanoparticles. Definition: first sentence of Wikipedia: Nanoparticle (CC BY-SA 4.0)
- Native state
- In biochemistry, the native state of a protein or nucleic acid is its properly folded and/or assembled form, which is operative and functional. Also: native. Definition: first sentence of Wikipedia: Native state (CC BY-SA 4.0)
- Necroptosis
- Necroptosis is a programmed form of necrosis and one of the many modalities of programmed cell death that has been described. Definition: first sentence of Wikipedia: Necroptosis (CC BY-SA 4.0)
- Nematode
- The nematodes, roundworms or eelworms constitute the phylum Nematoda (Νηματώδη; Nematoda). Also: nematodes. Definition: first sentence of Wikipedia: Nematode (CC BY-SA 4.0)
- Nesprin
- Nesprins (nuclear envelope spectrin repeat proteins) are a family of proteins that are found primarily in the outer nuclear membrane, as well as other subcellular compartments. Definition: first sentence of Wikipedia: Nesprin (CC BY-SA 4.0)
- Neural circuit
- A neural circuit is a population of neurons interconnected by synapses to carry out a specific function when activated. Also: neural circuits. Definition: first sentence of Wikipedia: Neural circuit (CC BY-SA 4.0)
- Neurodegenerative disease
- A neurodegenerative disease is caused by the progressive loss of neurons, in the process known as neurodegeneration. Also: neurodegenerative. Definition: first sentence of Wikipedia: Neurodegenerative disease (CC BY-SA 4.0)
- Neuroepithelial cell
- Neuroepithelial cells, or neuroectodermal cells, form the wall of the closed neural tube in early embryonic development. Definition: first sentence of Wikipedia: Neuroepithelial cell (CC BY-SA 4.0)
- Neurohormone
- A neurohormone is any hormone produced and released by neuroendocrine cells (also called neurosecretory cells) into the blood. Also: neurohormones. Definition: first sentence of Wikipedia: Neurohormone (CC BY-SA 4.0)
- Neuroimmune system
- The neuroimmune system is a system of structures and processes involving the biochemical and electrophysiological interactions between the nervous system and immune system which protect neurons from pathogens. Also: neuroimmune. Definition: first sentence of Wikipedia: Neuroimmune system (CC BY-SA 4.0)
- Neurological disorder
- A neurological disorder is any disorder of the nervous system. Also: neurological disorders. Definition: first sentence of Wikipedia: Neurological disorder (CC BY-SA 4.0)
- Neuromelanin
- Neuromelanin (NM) is a dark pigment found in the brain which is structurally related to melanin. Definition: first sentence of Wikipedia: Neuromelanin (CC BY-SA 4.0)
- Neuromodulation
- Neuromodulation is the physiological process by which a given neuron uses one or more chemicals to regulate diverse populations of neurons. Also: neuromodulator, neuromodulators. Definition: first sentence of Wikipedia: Neuromodulation (CC BY-SA 4.0)
- Neuron
- A neuron (American English), neurone (British English), or nerve cell, is a cell that is excitable, firing electric signals called action potentials. Also: neurons. Definition: first sentence of Wikipedia: Neuron (CC BY-SA 4.0)
- Neuropeptide
- Neuropeptides are chemical messengers made up of small chains of amino acids that are synthesized and released by neurons. Also: neuropeptides. Definition: first sentence of Wikipedia: Neuropeptide (CC BY-SA 4.0)
- Neurosteroid
- Neurosteroids, also known as neuroactive steroids, are endogenous or exogenous steroids that rapidly alter neuronal excitability through interaction with ligand-gated ion channels and other cell surface receptors. Also: neurosteroids. Definition: first sentence of Wikipedia: Neurosteroid (CC BY-SA 4.0)
- Neurotrophic factors
- Neurotrophic factors (NTFs) are a family of biomolecules – nearly all of which are peptides or small proteins – that support the growth, survival, and differentiation of both developing and mature neurons. Also: neurotrophic. Definition: first sentence of Wikipedia: Neurotrophic factors (CC BY-SA 4.0)
- NHL entry draft
- The NHL entry draft is held once every year, generally within two to three months after the conclusion of the previous regular season. Also: entry draft. Definition: first sentence of Wikipedia: NHL entry draft (CC BY-SA 4.0)
- Nicotinamide
- Nicotinamide (INN, BAN UK) or niacinamide (USAN US) (IUPAC name: 3-pyridinecarboxoamide) is a form of vitamin B3 found in food and used as a dietary supplement and medication. Definition: first sentence of Wikipedia: Nicotinamide (CC BY-SA 4.0)
- Nicotine
- Nicotine is a stimulant and alkaloid found primarily in plants of the nightshade family, notably in tobacco; it is also synthesized. Definition: first sentence of Wikipedia: Nicotine (CC BY-SA 4.0)
- Nicotinic acetylcholine receptor
- Nicotinic acetylcholine receptors, or nAChRs, are receptor polypeptides that respond to the neurotransmitter acetylcholine. Definition: first sentence of Wikipedia: Nicotinic acetylcholine receptor (CC BY-SA 4.0)
- Nictitating membrane
- The nictitating membrane (from Latin nictare, to blink) is a transparent or translucent third eyelid present in some animals that can be drawn across the eye from the medial canthus to protect and moisten it while maintaining vision. Also: nictitating membranes. Definition: first sentence of Wikipedia: Nictitating membrane (CC BY-SA 4.0)
- Nocturnal animal
- Nocturnality is a behavior in some non-human animals characterized by being active during the night and sleeping during the day. Also: nocturnal. Definition: first sentence of Wikipedia: Nocturnal animal (CC BY-SA 4.0)
- Non-covalent interaction
- In chemistry, a non-covalent interaction differs from a covalent bond in that it does not involve the sharing of electrons, but rather involves more dispersed variations of electromagnetic interactions between molecules or within a molecule. Also: non-covalent interactions. Definition: first sentence of Wikipedia: Non-covalent interaction (CC BY-SA 4.0)
- Norleucine
- Norleucine (abbreviated as Nle) is an amino acid with the formula CH3(CH2)3CH(NH2)CO2H. Definition: first sentence of Wikipedia: Norleucine (CC BY-SA 4.0)
- NPM1
- Nucleophosmin (NPM), also known as nucleolar phosphoprotein B23 or numatrin, is a protein that in humans is encoded by the NPM1 gene. Also: nucleophosmin. Definition: first sentence of Wikipedia: NPM1 (CC BY-SA 4.0)
- Nuclear lamina
- The nuclear lamina is a dense (~30 to 100 nm thick) fibrillar network inside the nucleus of eukaryote cells. Definition: first sentence of Wikipedia: Nuclear lamina (CC BY-SA 4.0)
- Nuclear pore complex
- The nuclear pore complex (NPC) is a large protein complex giving rise to the nuclear pore. Also: nuclear pore complexes. Definition: first sentence of Wikipedia: Nuclear pore complex (CC BY-SA 4.0)
- Nuclear receptor
- In the field of molecular biology, nuclear receptors are a class of proteins responsible for sensing steroids, thyroid hormones, vitamins, and certain other molecules. Also: nuclear receptors. Definition: first sentence of Wikipedia: Nuclear receptor (CC BY-SA 4.0)
- Nucleic acid double helix
- In molecular biology, the double helix is the structure formed by double-stranded molecules of nucleic acids such as DNA. Also: double helix. Definition: first sentence of Wikipedia: Nucleic acid double helix (CC BY-SA 4.0)
- Nucleic acid hybridization
- In molecular biology, hybridization (or hybridisation) is a phenomenon in which single-stranded deoxyribonucleic acid (DNA) or ribonucleic acid (RNA) molecules anneal to complementary DNA or RNA. Definition: first sentence of Wikipedia: Nucleic acid hybridization (CC BY-SA 4.0)
- Nucleic acid sequence
- A nucleic acid sequence is a succession of bases within the nucleotides forming alleles within a DNA (using GACT) or RNA (GACU) molecule. Definition: first sentence of Wikipedia: Nucleic acid sequence (CC BY-SA 4.0)
- Nucleoid
- The nucleoid (meaning nucleus-like) is an irregularly shaped region within the prokaryotic cell that contains all or most of the genetic material. Also: nucleoids. Definition: first sentence of Wikipedia: Nucleoid (CC BY-SA 4.0)
- Nucleolus organizer region
- Nucleolus organizer regions (American English) or nucleolus organiser regions (British English) (NORs) are chromosomal regions crucial for the formation of the nucleolus. Also: nucleolar organizing regions. Definition: first sentence of Wikipedia: Nucleolus organizer region (CC BY-SA 4.0)
- Nucleoplasm
- The nucleoplasm, also known as karyoplasm, is the type of protoplasm that makes up the cell nucleus, the most prominent organelle of the eukaryotic cell. Definition: first sentence of Wikipedia: Nucleoplasm (CC BY-SA 4.0)
- Nucleoporin
- Nucleoporins are a family of proteins which are the constituent building blocks of the nuclear pore complex (NPC). Also: nucleoporins. Definition: first sentence of Wikipedia: Nucleoporin (CC BY-SA 4.0)
- Nucleotide base
- Nucleotide bases (also nucleobases, nitrogenous bases) are nitrogen-containing biological compounds that form nucleosides, which, in turn, are components of nucleotides, with all of these monomers constituting the basic building blocks of nucleic acids. Also: nitrogenous base, nucleobase. Definition: first sentence of Wikipedia: Nucleotide base (CC BY-SA 4.0)
- Nucleus (neuroanatomy)
- In neuroanatomy, a nucleus is a cluster of neurons in the central nervous system, located deep within the cerebral hemispheres, brainstem and cerebellum. Also: nuclei. Definition: first sentence of Wikipedia: Nucleus (neuroanatomy) (CC BY-SA 4.0)
O
- Obesity
- Obesity is a medical condition, considered a disease by multiple organizations, in which excess body fat has accumulated to such an extent that it can have negative effects on health. Definition: first sentence of Wikipedia: Obesity (CC BY-SA 4.0)
- Oligocene
- The Oligocene is a geologic epoch of the Paleogene Period that extends from about 33.9 million to 23 million years before the present (33.9 to 23.04). Definition: first sentence of Wikipedia: Oligocene (CC BY-SA 4.0)
- Oligodendrocyte
- Oligodendrocytes, also known as oligodendroglia, are a type of neuroglia whose main function is to provide the myelin sheath to neuronal axons in the central nervous system (CNS). Also: oligodendrocytes. Definition: first sentence of Wikipedia: Oligodendrocyte (CC BY-SA 4.0)
- Oligopeptide
- An oligopeptide (oligo-, "a few"), is a peptide consisting of two to twenty amino acids, including dipeptides, tripeptides, tetrapeptides, and other polypeptides. Definition: first sentence of Wikipedia: Oligopeptide (CC BY-SA 4.0)
- Oligosaccharide
- An oligosaccharide is a saccharide polymer containing a small number (typically three to ten) of monosaccharides (simple sugars). Definition: first sentence of Wikipedia: Oligosaccharide (CC BY-SA 4.0)
- Oocyte
- An oocyte is a female germ cell involved in sexual reproduction. Also: oocytes. Definition: first sentence of Wikipedia: Oocyte (CC BY-SA 4.0)
- Open bolt
- A firearm is said to fire from an open bolt or open breech if, when ready to fire, the bolt and working parts are held to the rear of the receiver, with no round in the chamber. Definition: first sentence of Wikipedia: Open bolt (CC BY-SA 4.0)
- Organ (biology)
- In a multicellular organism, an organ is a collection of tissues joined in a structural unit to serve a common function. Also: organ, organs. Definition: first sentence of Wikipedia: Organ (biology) (CC BY-SA 4.0)
- Organic sulfide
- In organic chemistry, a sulfide (British English sulphide) or thioether is an organosulfur functional group with the connectivity as shown on right. Also: thioether. Definition: first sentence of Wikipedia: Organic sulfide (CC BY-SA 4.0)
- Organism
- An organism is any living thing that functions as an individual. Also: living organisms, organisms. Definition: first sentence of Wikipedia: Organism (CC BY-SA 4.0)
- Ornithine
- Ornithine is a non-proteinogenic α-amino acid that plays an essential role in the urea cycle (to the extent that it is sometimes also called the Ornithine Cycle). Definition: first sentence of Wikipedia: Ornithine (CC BY-SA 4.0)
- Ornithine cyclodeaminase
- The enzyme ornithine cyclodeaminase (EC 4.3.1.12) catalyzes the chemical reaction Definition: first sentence of Wikipedia: Ornithine cyclodeaminase (CC BY-SA 4.0)
- Outron
- An outron is a nucleotide sequence at the 5' end of the primary transcript of a gene that is removed by a special form of RNA splicing during maturation of the final RNA product. Also: outrons. Definition: first sentence of Wikipedia: Outron (CC BY-SA 4.0)
- Ovoviviparity
- Ovoviviparity, ovovivipary, ovivipary, internal oviparity, or aplacental viviparity is a "bridging" form of reproduction between egg-laying oviparous and live-bearing viviparous reproduction. Also: aplacental viviparity. Definition: first sentence of Wikipedia: Ovoviviparity (CC BY-SA 4.0)
- Oxidative phosphorylation
- Oxidative phosphorylation or electron transport-linked phosphorylation or terminal oxidation, is the metabolic pathway in which cells use enzymes to oxidize nutrients, thereby releasing chemical energy in order to produce adenosine triphosphate (ATP). Definition: first sentence of Wikipedia: Oxidative phosphorylation (CC BY-SA 4.0)
- Oxidative stress
- Oxidative stress reflects an imbalance between the systemic manifestation of reactive oxygen species and a biological system's ability to readily detoxify the reactive intermediates or to repair the resulting damage. Definition: first sentence of Wikipedia: Oxidative stress (CC BY-SA 4.0)
- Oxygen
- Oxygen is a chemical element; it has the symbolO and its atomic number is8. Definition: first sentence of Wikipedia: Oxygen (CC BY-SA 4.0)
P
- Palm oil
- Palm oil is an edible vegetable oil derived from the reddish mesocarp (pulp) of the fruit of the African oil palm. Also: palm fruits. Definition: first sentence of Wikipedia: Palm oil (CC BY-SA 4.0)
- Parasitism
- Parasitism is a close relationship between species, where one organism, the parasite, lives (at least some of the time) on or inside another organism, the host, causing it some harm, and is adapted structurally to this way of life. Also: parasite, parasites. Definition: first sentence of Wikipedia: Parasitism (CC BY-SA 4.0)
- Parent structure
- In chemistry, a parent structure is the structure of an unadorned ion or molecule from which derivatives can be visualized. Also: core structure. Definition: first sentence of Wikipedia: Parent structure (CC BY-SA 4.0)
- Particulate matter
- Particulate matter (PM) or particulates are microscopic particles of solid or liquid matter suspended in the air. Also: particles. Definition: first sentence of Wikipedia: Particulate matter (CC BY-SA 4.0)
- Pathogen
- In biology, a pathogen, in the oldest and broadest sense, is any organism, agent or micro-organism that can produce disease. Also: pathogenic, pathogens. Definition: first sentence of Wikipedia: Pathogen (CC BY-SA 4.0)
- Pelagic zone
- The pelagic zone consists of the water column of the open ocean and can be further divided into regions by depth. Also: pelagic. Definition: first sentence of Wikipedia: Pelagic zone (CC BY-SA 4.0)
- Pentose
- In chemistry, a pentose is a monosaccharide (simple sugar) with five carbon atoms. Also: five-carbon sugar. Definition: first sentence of Wikipedia: Pentose (CC BY-SA 4.0)
- Peptide bond
- In organic chemistry, a peptide bond is an amide type of covalent chemical bond linking two consecutive alpha-amino acids from C1 (carbon number one) of one alpha-amino acid and N2 (nitrogen number two) of another, along a peptide or protein chain. Definition: first sentence of Wikipedia: Peptide bond (CC BY-SA 4.0)
- Peptide hormone
- Peptide hormones are hormones composed of peptide molecules. Also: peptide hormones. Definition: first sentence of Wikipedia: Peptide hormone (CC BY-SA 4.0)
- Phagocyte
- Phagocytes are cells that protect the body by ingesting harmful foreign particles, bacteria, and dead or dying cells. Also: phagocytes. Definition: first sentence of Wikipedia: Phagocyte (CC BY-SA 4.0)
- Phagocytosis
- Phagocytosis is the process by which a cell uses its plasma membrane to engulf a large particle (≥ 0.5 μm), giving rise to an internal compartment called the phagosome. Also: phagocytic. Definition: first sentence of Wikipedia: Phagocytosis (CC BY-SA 4.0)
- Phagosome
- In cell biology, a phagosome is a vesicle formed around a particle engulfed by a phagocyte via phagocytosis. Also: phagosomes. Definition: first sentence of Wikipedia: Phagosome (CC BY-SA 4.0)
- Phase (matter)
- In the physical sciences, a phase is a region of material that is chemically uniform, physically distinct, and (often) mechanically separable. Also: phase. Definition: first sentence of Wikipedia: Phase (matter) (CC BY-SA 4.0)
- Phase separation
- Phase separation is the creation of two distinct phases from a single homogeneous mixture. Definition: first sentence of Wikipedia: Phase separation (CC BY-SA 4.0)
- Phenethylamine
- Phenethylamine (PEA) is an organic compound, natural monoamine alkaloid, and trace amine, which acts as a central nervous system stimulant in humans. Definition: first sentence of Wikipedia: Phenethylamine (CC BY-SA 4.0)
- Phenotype
- In genetics, the phenotype is the set of observable characteristics or traits of an organism. Also: phenotypic. Definition: first sentence of Wikipedia: Phenotype (CC BY-SA 4.0)
- Phenyl group
- In organic chemistry, the phenyl group, or phenyl ring, is a cyclic group of atoms with the formula, and is often represented by the pseudoelement symbol Ph (archaically φ) or Ø. Also: phenyl. Definition: first sentence of Wikipedia: Phenyl group (CC BY-SA 4.0)
- Phosphate
- A phosphate is an anion, salt, functional group or ester derived from a phosphoric acid. Also: phosphate group. Definition: first sentence of Wikipedia: Phosphate (CC BY-SA 4.0)
- Phosphodiester bond
- In chemistry, a phosphodiester bond occurs when exactly two of the hydroxyl groups in phosphoric acid react with hydroxyl groups on other molecules to form two ester bonds. Also: phosphodiester bonds. Definition: first sentence of Wikipedia: Phosphodiester bond (CC BY-SA 4.0)
- Phosphorylation
- In biochemistry, phosphorylation is described as the "transfer of a phosphate group" from a donor to an acceptor or the addition of a phosphate group to a molecule. Definition: first sentence of Wikipedia: Phosphorylation (CC BY-SA 4.0)
- Photon
- A photon is an elementary particle that is a quantum of the electromagnetic field, including electromagnetic radiation such as light and radio waves, and the force carrier for the electromagnetic force. Also: photons. Definition: first sentence of Wikipedia: Photon (CC BY-SA 4.0)
- Photophosphorylation
- Photophosphorylation is the process of phosphorylation of ADP to form ATP using the energy from photons (e.g. from sunlight) in photosynthesis. Definition: first sentence of Wikipedia: Photophosphorylation (CC BY-SA 4.0)
- Photopic vision
- Photopic vision is the vision of the eye under well-lit conditions (luminance levels from 10 to 108 cd/m2). Definition: first sentence of Wikipedia: Photopic vision (CC BY-SA 4.0)
- Photoreceptor protein
- Photoreceptor proteins are light-sensitive proteins involved in the sensing and response to light in a variety of organisms. Also: photoreceptor proteins. Definition: first sentence of Wikipedia: Photoreceptor protein (CC BY-SA 4.0)
- Photosynthetic pigment
- A photosynthetic pigment (accessory pigment; chloroplast pigment; antenna pigment) is a pigment that is present in chloroplasts or photosynthetic bacteria and captures the light energy necessary for photosynthesis. Also: photosynthetic pigments. Definition: first sentence of Wikipedia: Photosynthetic pigment (CC BY-SA 4.0)
- Phylogenetics
- In biology, phylogenetics is the study of the evolutionary history of life using observable characteristics of organisms (or genes), which is known as phylogenetic inference. Also: phylogenetic. Definition: first sentence of Wikipedia: Phylogenetics (CC BY-SA 4.0)
- Physical system
- A physical system is a collection of physical objects under study. Also: system. Definition: first sentence of Wikipedia: Physical system (CC BY-SA 4.0)
- Physiology
- Physiology is the scientific study of functions and mechanisms in a living system. Also: physiological. Definition: first sentence of Wikipedia: Physiology (CC BY-SA 4.0)
- Phytoplankton
- Phytoplankton are the autotrophic (self-feeding) components of the plankton community and a key part of ocean and freshwater ecosystems. Definition: first sentence of Wikipedia: Phytoplankton (CC BY-SA 4.0)
- Picatinny rail
- The Picatinny rail (MIL-STD-1913 rail or 1913 rail) is an American rail integration system designed by Richard Swan that provides a mounting platform for firearm accessories. Definition: first sentence of Wikipedia: Picatinny rail (CC BY-SA 4.0)
- Pilus
- A pilus (Latin for 'hair';: pili) is a hair-like cell-surface appendage found on many bacteria and archaea. Definition: first sentence of Wikipedia: Pilus (CC BY-SA 4.0)
- Placenta
- The placenta is a temporary embryonic and later fetal organ that begins developing from the blastocyst shortly after implantation. Also: placental. Definition: first sentence of Wikipedia: Placenta (CC BY-SA 4.0)
- Plant cuticle
- A plant cuticle is a protecting film covering the outermost skin layer (epidermis) of leaves, young shoots and other aerial plant organs (aerial here meaning all plant parts not embedded in soil or other substrate) that have no periderm. Definition: first sentence of Wikipedia: Plant cuticle (CC BY-SA 4.0)
- Plant litter
- Plant litter (also leaf litter, tree litter, soil litter, litterfall, or duff) is dead plant material (such as leaves, bark, needles, twigs, and cladodes) that has fallen on the top layer of soil, commonly known as the litter layer or O-horizon ("O" for "organic"). Also: leaf litter. Definition: first sentence of Wikipedia: Plant litter (CC BY-SA 4.0)
- Plasma cell
- Plasma cells, also called plasma B cells or effector B cells, are white blood cells that originate in the lymphoid organs as B cells and secrete large quantities of proteins called antibodies in response to being presented with specific substances called antigens. Also: plasma cells. Definition: first sentence of Wikipedia: Plasma cell (CC BY-SA 4.0)
- Plasmalogen
- Plasmalogens are a class of glycerophospholipid with a plasmenyl group linked to a lipid at the sn-1 position of the glycerol backbone. Also: plasmalogens. Definition: first sentence of Wikipedia: Plasmalogen (CC BY-SA 4.0)
- Platelet
- Platelets or thrombocytes are a part of blood whose function (along with the coagulation factors) is to react to bleeding from blood vessel injury by clumping to form a blood clot. Also: platelets. Definition: first sentence of Wikipedia: Platelet (CC BY-SA 4.0)
- Pleistocene
- The Pleistocene is the geological epoch that lasted from c. 2.58 million to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Definition: first sentence of Wikipedia: Pleistocene (CC BY-SA 4.0)
- Polarized membrane
- A polarized membrane is a lipid membrane that has a positive electrical charge on one side and a negative charge on another side, which produces the resting potential in living cells. Also: membranes, polar membrane. Definition: first sentence of Wikipedia: Polarized membrane (CC BY-SA 4.0)
- Polyadenylation
- Polyadenylation is the addition of a poly(A) tail to an RNA transcript, typically a messenger RNA (mRNA). Also: polyadenylated. Definition: first sentence of Wikipedia: Polyadenylation (CC BY-SA 4.0)
- Polyamine
- Polyamines are a type of organic compound having two or more amino groups. Also: polyamines. Definition: first sentence of Wikipedia: Polyamine (CC BY-SA 4.0)
- Polymer
- A polymer is a substance or material that consists of very large molecules, or macromolecules, that are constituted by many repeating subunits derived from one or more species of monomers. Also: polymers. Definition: first sentence of Wikipedia: Polymer (CC BY-SA 4.0)
- Polymerase
- In biochemistry, a polymerase is an enzyme (EC 2.7.7.6/7/19/48/49) that synthesizes long chains of polymers or nucleic acids. Definition: first sentence of Wikipedia: Polymerase (CC BY-SA 4.0)
- Polymerization
- In polymer chemistry, polymerization (American English), or polymerisation (British English), is a process of reacting monomer molecules together in a chemical reaction to form polymer chains or three-dimensional networks. Definition: first sentence of Wikipedia: Polymerization (CC BY-SA 4.0)
- Polyphosphate
- A polyphosphate is a salt or ester of polymeric oxyanions formed from tetrahedral PO4 (phosphate) structural units linked together by sharing oxygen atoms. Definition: first sentence of Wikipedia: Polyphosphate (CC BY-SA 4.0)
- Polypyrimidine tract
- The polypyrimidine tract is a region of pre-messenger RNA (mRNA) that promotes the assembly of the spliceosome, the protein complex specialized for carrying out RNA splicing during the process of post-transcriptional modification. Definition: first sentence of Wikipedia: Polypyrimidine tract (CC BY-SA 4.0)
- Power play
- Power play is a term used in various team sports to describe a period of play when one team is given an advantage. Definition: first sentence of Wikipedia: Power play (CC BY-SA 4.0)
- Precursor cell
- In cell biology, precursor cells—also called blast cells—are partially differentiated, or intermediate, and are sometimes referred to as progenitor cells. Also: precursor. Definition: first sentence of Wikipedia: Precursor cell (CC BY-SA 4.0)
- Pregnancy
- Pregnancy is the time during which one or more offspring gestates inside a woman's uterus. Definition: first sentence of Wikipedia: Pregnancy (CC BY-SA 4.0)
- Pregnane
- Pregnane, also known as 17β-ethylandrostane or as 10β,13β-dimethyl-17β-ethylgonane, is a C21 steroid and, indirectly, a parent of progesterone. Definition: first sentence of Wikipedia: Pregnane (CC BY-SA 4.0)
- Prenylation
- Prenylation (also known as isoprenylation or lipidation) is the addition of hydrophobic molecules to a protein or a biomolecule. Also: prenyl. Definition: first sentence of Wikipedia: Prenylation (CC BY-SA 4.0)
- Primary transcript
- A primary transcript is the single-stranded ribonucleic acid (RNA) product synthesized by transcription of DNA, and processed to yield various mature RNA products such as mRNAs, tRNAs, and rRNAs. Definition: first sentence of Wikipedia: Primary transcript (CC BY-SA 4.0)
- Primer (molecular biology)
- A primer is a short, single-stranded nucleic acid used by all living organisms in the initiation of DNA synthesis. Also: primer. Definition: first sentence of Wikipedia: Primer (molecular biology) (CC BY-SA 4.0)
- Principle of univariance
- The principle of univariance states that a single class of photoreceptors cannot unambiguously determine either the wavelength or intensity of incident light. Definition: first sentence of Wikipedia: Principle of univariance (CC BY-SA 4.0)
- Prion
- A prion is a misfolded protein that induces folding problems in normal variants of the same protein, leading to cellular death. Also: prions. Definition: first sentence of Wikipedia: Prion (CC BY-SA 4.0)
- Progesterone receptor
- The progesterone receptor (PR), also known as NR3C3 or nuclear receptor subfamily 3, group C, member 3, is a protein found inside cells. Also: nuclear progesterone receptor, progesterone receptors. Definition: first sentence of Wikipedia: Progesterone receptor (CC BY-SA 4.0)
- Prognosis
- A prognosis is made on the basis of the normal course of the diagnosed disease, the individual's physical and mental condition, the available treatments, and additional factors. Definition: first sentence of Wikipedia: Prognosis (CC BY-SA 4.0)
- Prohormone
- Prohormones can travel the blood stream as a hormone in an inactivated form, ready to be activated later in the cell by post-translational modification. Also: prohormones. Definition: first sentence of Wikipedia: Prohormone (CC BY-SA 4.0)
- Proofreading (biology)
- The term proofreading is used in genetics to refer to the error-correcting processes, first proposed by John Hopfield and Jacques Ninio, involved in DNA replication, immune system specificity, and enzyme-substrate recognition among many other processes that require enhanced specificity. Also: proofreading. Definition: first sentence of Wikipedia: Proofreading (biology) (CC BY-SA 4.0)
- Protease
- A protease (also called a peptidase, proteinase, or proteolytic enzyme) is an enzyme that catalyzes proteolysis, breaking down proteins into smaller polypeptides or single amino acids, and spurring the formation of new protein products. Also: proteases. Definition: first sentence of Wikipedia: Protease (CC BY-SA 4.0)
- Protein complex
- A protein complex or multiprotein complex is a group of two or more associated polypeptide chains. Also: complexes, protein complexes. Definition: first sentence of Wikipedia: Protein complex (CC BY-SA 4.0)
- Protein dimer
- In biochemistry, a protein dimer is a macromolecular complex or multimer formed by two protein monomers, or single proteins, which are usually non-covalently bound. Also: dimer, dimers. Definition: first sentence of Wikipedia: Protein dimer (CC BY-SA 4.0)
- Protein primary structure
- Protein primary structure is the linear sequence of amino acids in a peptide or protein. Also: amino acid sequence, primary structure, sequence. Definition: first sentence of Wikipedia: Protein primary structure (CC BY-SA 4.0)
- Protein secondary structure
- Protein secondary structure is the local spatial conformation of the polypeptide backbone excluding the side chains. Also: secondary structures. Definition: first sentence of Wikipedia: Protein secondary structure (CC BY-SA 4.0)
- Protein tertiary structure
- Protein tertiary structure is the three-dimensional shape of a protein. Also: tertiary structure, three-dimensional structure. Definition: first sentence of Wikipedia: Protein tertiary structure (CC BY-SA 4.0)
- Protein turnover
- In cell biology, protein turnover refers to the replacement of older proteins as they are broken down within the cell. Definition: first sentence of Wikipedia: Protein turnover (CC BY-SA 4.0)
- Proteinogenic amino acid
- Proteinogenic amino acids are amino acids that are incorporated biosynthetically into proteins during translation from RNA. Also: proteinogenic amino acids. Definition: first sentence of Wikipedia: Proteinogenic amino acid (CC BY-SA 4.0)
- Protein–energy malnutrition
- Protein–energy undernutrition (PEU), once called protein–energy malnutrition (PEM), is a form of malnutrition that is defined as a range of conditions arising from coincident lack of dietary protein and/or energy (calories) in varying proportions. Also: protein-energy malnutrition. Definition: first sentence of Wikipedia: Protein–energy malnutrition (CC BY-SA 4.0)
- Proteolysis
- Proteolysis is the breakdown of proteins into smaller polypeptides or amino acids. Definition: first sentence of Wikipedia: Proteolysis (CC BY-SA 4.0)
- Protist
- A protist or protoctist is any eukaryotic organism that is not an animal, land plant, or fungus. Also: protists. Definition: first sentence of Wikipedia: Protist (CC BY-SA 4.0)
- Proton
- A proton is a stable subatomic particle, symbol, H+, or 1H+ with a positive electric charge of +1 e (elementary charge). Also: protons. Definition: first sentence of Wikipedia: Proton (CC BY-SA 4.0)
- Protoplasm
- Protoplasm is the part of a cell that is surrounded by a plasma membrane. Definition: first sentence of Wikipedia: Protoplasm (CC BY-SA 4.0)
- Protozoa
- Protozoa are a polyphyletic group of single-celled eukaryotes, either free-living or parasitic, that feed on organic matter such as other microorganisms or organic debris. Definition: first sentence of Wikipedia: Protozoa (CC BY-SA 4.0)
- Pupillary reflex
- Pupillary reflex refers to one of the reflexes associated with pupillary function. Definition: first sentence of Wikipedia: Pupillary reflex (CC BY-SA 4.0)
- Purine
- Purine is a heterocyclic aromatic organic compound that consists of two rings (pyrimidine and imidazole) fused together. Definition: first sentence of Wikipedia: Purine (CC BY-SA 4.0)
- Pyomelanin
- Pyomelanin is one of the five basic types of melanin. Definition: first sentence of Wikipedia: Pyomelanin (CC BY-SA 4.0)
- Pyrrolidine
- Pyrrolidine, also known as tetrahydropyrrole, is an organic compound with the molecular formula (CH2)4NH. Definition: first sentence of Wikipedia: Pyrrolidine (CC BY-SA 4.0)
- Pyrrolysine
- Pyrrolysine (symbol Pyl or O), encoded by the "amber" stop codon UAG, is a proteinogenic amino acid that is used in some methanogenic archaea and in bacteria. Definition: first sentence of Wikipedia: Pyrrolysine (CC BY-SA 4.0)
Q
- Quantasome
- Quantasomes are particles found in the thylakoid membrane of chloroplasts in which photosynthesis takes place. Also: quantasomes. Definition: first sentence of Wikipedia: Quantasome (CC BY-SA 4.0)
R
- Racemic mixture
- In chemistry, a racemic mixture or racemate is a mixture that has equal amounts (50:50) of left- and right-handed enantiomers of a chiral molecule or salt. Definition: first sentence of Wikipedia: Racemic mixture (CC BY-SA 4.0)
- Random coil
- In polymer chemistry, a random coil is a conformation of polymers where the monomer subunits are oriented randomly while still being bonded to adjacent units. Definition: first sentence of Wikipedia: Random coil (CC BY-SA 4.0)
- Rate of fire
- Rate of fire is the frequency at which a specific weapon can fire or launch its projectiles. Definition: first sentence of Wikipedia: Rate of fire (CC BY-SA 4.0)
- Recreational fishing
- Recreational fishing, also called sport fishing or game fishing, is fishing for leisure, exercise or competition. Definition: first sentence of Wikipedia: Recreational fishing (CC BY-SA 4.0)
- Reducing agent
- In chemistry, a reducing agent (also known as a reductant, reducer, or electron donor) is a chemical species that "donates" an electron to an electron recipient (called the oxidizing agent, oxidant, oxidizer, or electron acceptor). Definition: first sentence of Wikipedia: Reducing agent (CC BY-SA 4.0)
- Replicon (genetics)
- A replicon is a region of an organism's genome that is independently replicated from a single origin of replication. Also: replicons. Definition: first sentence of Wikipedia: Replicon (genetics) (CC BY-SA 4.0)
- Residue (chemistry)
- In chemistry, residue has different meanings. Also: residues. Definition: first sentence of Wikipedia: Residue (chemistry) (CC BY-SA 4.0)
- Resistor
- A resistor is a passive two-terminal electronic component that implements electrical resistance as a circuit element. Also: resistors. Definition: first sentence of Wikipedia: Resistor (CC BY-SA 4.0)
- Respiration (physiology)
- In physiology, respiration is a biological process that facilitates the transport of oxygen from the outside environment to bodily tissues and the removal of carbon dioxide of an organism using a respiratory system. Also: respiration. Definition: first sentence of Wikipedia: Respiration (physiology) (CC BY-SA 4.0)
- Resting potential
- The relatively static membrane potential of quiescent cells is called the resting membrane potential (or resting voltage), as opposed to the specific dynamic electrochemical phenomena called action potential and graded membrane potential. Definition: first sentence of Wikipedia: Resting potential (CC BY-SA 4.0)
- Reticulocyte
- In hematology, reticulocytes are immature red blood cells (RBCs). Also: reticulocytes. Definition: first sentence of Wikipedia: Reticulocyte (CC BY-SA 4.0)
- Retina
- The retina is the innermost, light-sensitive layer of tissue of the eye. Definition: first sentence of Wikipedia: Retina (CC BY-SA 4.0)
- Ribonuclease
- Ribonuclease (commonly abbreviated RNase) is a type of nuclease that catalyzes the degradation of RNA into smaller components. Also: ribonucleases. Definition: first sentence of Wikipedia: Ribonuclease (CC BY-SA 4.0)
- Ribonucleoprotein particle
- A ribonucleoprotein particle (RNP) is a complex formed between RNA and RNA-binding proteins (RBPs). Definition: first sentence of Wikipedia: Ribonucleoprotein particle (CC BY-SA 4.0)
- Ribonucleotide
- In biochemistry, a ribonucleotide is a nucleotide containing ribose as its pentose component. Also: ribonucleotides. Definition: first sentence of Wikipedia: Ribonucleotide (CC BY-SA 4.0)
- Ribosomal protein
- A ribosomal protein (r-protein or rProtein) is any of the proteins that, in conjunction with rRNA, make up the ribosomal subunits involved in the cellular process of translation. Also: ribosomal proteins. Definition: first sentence of Wikipedia: Ribosomal protein (CC BY-SA 4.0)
- Ribosome biogenesis
- Ribosome biogenesis is the process of making ribosomes. Definition: first sentence of Wikipedia: Ribosome biogenesis (CC BY-SA 4.0)
- Ribozyme
- Ribozymes (ribonucleic acid enzymes) are RNA molecules that have the ability to catalyze specific biochemical reactions, including RNA splicing in gene expression, similar to the action of protein enzymes. Also: ribozymes. Definition: first sentence of Wikipedia: Ribozyme (CC BY-SA 4.0)
S
- Safranin
- Safranin (Safranin O or basic red 2) is a biological stain used in histology and cytology. Definition: first sentence of Wikipedia: Safranin (CC BY-SA 4.0)
- Salary cap
- In professional sports, a salary cap (or wage cap) is an agreement or rule that places a limit on the amount of money that a team can spend on players' salaries. Definition: first sentence of Wikipedia: Salary cap (CC BY-SA 4.0)
- Saltatory conduction
- In neuroscience, saltatory conduction is the propagation of action potentials along myelinated axons from one node of Ranvier to the next, increasing the conduction velocity of action potentials. Definition: first sentence of Wikipedia: Saltatory conduction (CC BY-SA 4.0)
- Sarcolemma
- The sarcolemma (sarco (from sarx) from Greek; flesh, and lemma from Greek; sheath), also called the myolemma, is the cell membrane surrounding a skeletal muscle fibre or a cardiomyocyte. Definition: first sentence of Wikipedia: Sarcolemma (CC BY-SA 4.0)
- Sarcoplasmic reticulum
- The sarcoplasmic reticulum (SR) is a membrane-bound organelle found within muscle cells that is similar to the smooth endoplasmic reticulum in other cells. Definition: first sentence of Wikipedia: Sarcoplasmic reticulum (CC BY-SA 4.0)
- Scotopic vision
- In vision science, scotopic vision or scotopia is the visual perception of the eyes under low-light conditions. Definition: first sentence of Wikipedia: Scotopic vision (CC BY-SA 4.0)
- Seaweed oil
- Seaweed oil, also called algae oil or algal oil, is used for making food, with the purified product almost colorless and odorless. Also: algae oil. Definition: first sentence of Wikipedia: Seaweed oil (CC BY-SA 4.0)
- Secondary metabolism
- In biochemistry, secondary metabolism (also called specialized metabolism) is a term for pathways and small molecule products of metabolism that are involved in ecological interactions, but are not absolutely required for the survival of the organism. Definition: first sentence of Wikipedia: Secondary metabolism (CC BY-SA 4.0)
- Secondary sex characteristic
- A secondary sex characteristic (or secondary sexual characteristic) is a physical characteristic of an organism that is related to or derived from its sex, but not directly part of its reproductive system. Also: sexual characteristics. Definition: first sentence of Wikipedia: Secondary sex characteristic (CC BY-SA 4.0)
- Secretion
- Secretion is the movement of material from one point to another, such as a secreted chemical substance from a cell or gland. Also: secretory. Definition: first sentence of Wikipedia: Secretion (CC BY-SA 4.0)
- Select fire
- Select fire is the capability of a weapon to be adjusted to fire in semi-automatic, fully automatic, or burst mode. Also: select-fire, selective fire. Definition: first sentence of Wikipedia: Select fire (CC BY-SA 4.0)
- Selenocysteine
- Selenocysteine (symbol Sec or U, in older publications also as Se-Cys) is the 21st proteinogenic amino acid. Definition: first sentence of Wikipedia: Selenocysteine (CC BY-SA 4.0)
- Semiaquatic
- In biology, being semiaquatic refers to various macro-organisms that live regularly in both aquatic and terrestrial environments. Definition: first sentence of Wikipedia: Semiaquatic (CC BY-SA 4.0)
- Semipermeable membrane
- Semipermeable membrane is a type of synthetic or biologic, polymeric membrane that allows certain molecules or ions to pass through it by osmosis. Also: selectively permeable membrane. Definition: first sentence of Wikipedia: Semipermeable membrane (CC BY-SA 4.0)
- Senescence
- Senescence or biological aging is the gradual deterioration of functional characteristics in living organisms. Definition: first sentence of Wikipedia: Senescence (CC BY-SA 4.0)
- Sense
- A sense is a biological system used by an organism for sensation, the process of gathering information about the surroundings through the detection of stimuli. Also: senses. Definition: first sentence of Wikipedia: Sense (CC BY-SA 4.0)
- Sense (molecular biology)
- In molecular biology and genetics, the sense of a nucleic acid molecule, particularly of a strand of DNA or RNA, refers to the nature of the roles of the strand and its complement in specifying a sequence of amino acids. Also: negative-sense, sense. Definition: first sentence of Wikipedia: Sense (molecular biology) (CC BY-SA 4.0)
- Septic shock
- Septic shock is a potentially fatal medical condition that occurs when sepsis, which is defined as an abnormal immune response to infection that leads to life-threatening organ dysfunction, leads to dangerously low blood pressure and abnormalities in cellular and metabolic dysfunction. Definition: first sentence of Wikipedia: Septic shock (CC BY-SA 4.0)
- Serotonin
- Serotonin, also known as 5-hydroxytryptamine (5-HT), is a monoamine neurotransmitter with a wide range of functions in both the central nervous system (CNS) and also peripheral tissues. Definition: first sentence of Wikipedia: Serotonin (CC BY-SA 4.0)
- Serotype
- A serotype or serovar is a distinct variation within a species of bacteria or virus or among immune cells of different individuals. Also: serotyping. Definition: first sentence of Wikipedia: Serotype (CC BY-SA 4.0)
- Serous fluid
- In physiology, serous fluid or serosal fluid (originating from the Medieval Latin word serosus, from Latin serum) is any of various body fluids resembling serum, that are typically pale yellow or transparent and of a benign nature. Also: serous. Definition: first sentence of Wikipedia: Serous fluid (CC BY-SA 4.0)
- Serration
- Serration is a saw-like appearance or a row of sharp or tooth-like projections. Also: serrated, serrations. Definition: first sentence of Wikipedia: Serration (CC BY-SA 4.0)
- Sex hormone
- Sex hormones, also known as sex steroids, gonadocorticoids and gonadal steroids, are steroid hormones that interact with vertebrate steroid hormone receptors. Also: sex hormones, sex steroids. Definition: first sentence of Wikipedia: Sex hormone (CC BY-SA 4.0)
- Sex hormone–binding globulin
- Sex hormone-binding globulin (SHBG) or sex steroid-binding globulin (SSBG) is a glycoprotein that binds to androgens and estrogens. Also: sex hormone-binding globulin. Definition: first sentence of Wikipedia: Sex hormone–binding globulin (CC BY-SA 4.0)
- Sex pheromone
- Sex pheromones are pheromones released by an organism to attract an individual of the same species, encourage it to mate with it, or perform some other function closely related with sexual reproduction. Also: sex pheromones. Definition: first sentence of Wikipedia: Sex pheromone (CC BY-SA 4.0)
- Sexual dimorphism
- Sexual dimorphism is the condition where different sexes of the same species exhibit different morphological characteristics, including characteristics not directly involved in reproduction. Definition: first sentence of Wikipedia: Sexual dimorphism (CC BY-SA 4.0)
- Short-handed
- Short-handed is a term used in ice hockey and several related sports, including water polo, and refers to having fewer players on the ice during play, as a result of a penalty. Also: shorthanded. Definition: first sentence of Wikipedia: Short-handed (CC BY-SA 4.0)
- Side chain
- In organic chemistry and biochemistry, a side chain is a chemical group that is attached to a core part of the molecule called the "main chain" or backbone. Also: side chains. Definition: first sentence of Wikipedia: Side chain (CC BY-SA 4.0)
- Signal patch
- A protein signal patch contains information to send a given protein to a location in the cell. Also: signal patches. Definition: first sentence of Wikipedia: Signal patch (CC BY-SA 4.0)
- Signal peptidase
- Signal peptidases are enzymes that convert secretory and some membrane proteins to their mature or pro forms by cleaving their signal peptides from their N-termini. Definition: first sentence of Wikipedia: Signal peptidase (CC BY-SA 4.0)
- Signal recognition particle
- The signal recognition particle (SRP) is an abundant, cytosolic, universally conserved ribonucleoprotein (protein-RNA complex) that recognizes and targets specific proteins to the endoplasmic reticulum in eukaryotes and the plasma membrane in prokaryotes. Also: signal recognition particles. Definition: first sentence of Wikipedia: Signal recognition particle (CC BY-SA 4.0)
- Silencer (genetics)
- In genetics, a silencer is a DNA sequence capable of binding transcription regulation factors, called repressors. Also: silencers. Definition: first sentence of Wikipedia: Silencer (genetics) (CC BY-SA 4.0)
- Sister group
- In phylogenetics, a sister group or sister taxon, also called an adelphotaxon, comprises the closest relative(s) of another given unit in an evolutionary tree. Definition: first sentence of Wikipedia: Sister group (CC BY-SA 4.0)
- Skeletal muscle
- Skeletal muscle (commonly referred to as muscle) is one of the three types of vertebrate muscle tissue, the others being cardiac muscle and smooth muscle. Also: skeletal. Definition: first sentence of Wikipedia: Skeletal muscle (CC BY-SA 4.0)
- Small molecule
- In molecular biology and pharmacology, a small molecule or micromolecule is a low molecular weight (≤ 1000 daltons) organic compound that may regulate a biological process, with a size on the order of 1 nm. Definition: first sentence of Wikipedia: Small molecule (CC BY-SA 4.0)
- Soil organic matter
- Soil organic matter (SOM) is the organic matter component of soil, consisting of plant and animal detritus at various stages of decomposition, cells and tissues of soil microbes, and substances that soil microbes synthesize. Definition: first sentence of Wikipedia: Soil organic matter (CC BY-SA 4.0)
- Solution (chemistry)
- In chemistry, a solution is defined by IUPAC as "A liquid or solid phase containing more than one substance, when for convenience one (or more) substance, which is called the solvent, is treated differently from the other substances, which are called solutes. Also: solutes. Definition: first sentence of Wikipedia: Solution (chemistry) (CC BY-SA 4.0)
- Solvent
- A solvent (from the Latin solvō, "loosen, untie, solve") is a substance that dissolves a solute, resulting in a solution. Also: nonpolar solvents. Definition: first sentence of Wikipedia: Solvent (CC BY-SA 4.0)
- Soma (biology)
- In cellular neuroscience, the soma, or cell body, is the bulbous, non-process portion of a neuron or glial cell that contains the cell nucleus. Also: cell body. Definition: first sentence of Wikipedia: Soma (biology) (CC BY-SA 4.0)
- Somatic (biology)
- In cellular biology, the term somatic is derived from the French somatique which comes from the Ancient Greek σωματικός (sōmatikós, 'bodily') and σῶμα (sôma, 'body'). Also: somatic. Definition: first sentence of Wikipedia: Somatic (biology) (CC BY-SA 4.0)
- Special forces
- Special forces or special operations forces (SOF) are military units trained to conduct special operations. Definition: first sentence of Wikipedia: Special forces (CC BY-SA 4.0)
- Spectral sensitivity
- Spectral sensitivity is the relative efficiency of detection, of light or other signal, as a function of the frequency or wavelength of the signal. Definition: first sentence of Wikipedia: Spectral sensitivity (CC BY-SA 4.0)
- Spinal cord
- The spinal cord is a long, thin, tubular structure made up of nervous tissue that extends from the medulla oblongata in the lower brainstem to the lumbar region of the vertebral column (backbone) of vertebrate animals. Definition: first sentence of Wikipedia: Spinal cord (CC BY-SA 4.0)
- Spindle apparatus
- In cell biology, the spindle apparatus is the cytoskeletal structure of eukaryotic cells that forms during cell division to separate sister chromatids between daughter cells. Also: mitotic spindles. Definition: first sentence of Wikipedia: Spindle apparatus (CC BY-SA 4.0)
- Spiracle (vertebrates)
- Spiracles are openings on the surface of some animals, which usually lead to respiratory systems. Also: spiracle, spiracles. Definition: first sentence of Wikipedia: Spiracle (vertebrates) (CC BY-SA 4.0)
- Spleen
- The spleen, or milt, is an organ found in almost all vertebrates. Definition: first sentence of Wikipedia: Spleen (CC BY-SA 4.0)
- Spliceosome
- A spliceosome is a large ribonucleoprotein (RNP) complex found primarily within the nucleus of eukaryotic cells. Definition: first sentence of Wikipedia: Spliceosome (CC BY-SA 4.0)
- Sponge
- Sponges or sea sponges are primarily marine invertebrates of the animal phylum Porifera. Also: sponges. Definition: first sentence of Wikipedia: Sponge (CC BY-SA 4.0)
- Staining
- Staining is a technique used to enhance contrast in samples, generally at the microscopic level. Also: stained. Definition: first sentence of Wikipedia: Staining (CC BY-SA 4.0)
- Start codon
- The start codon is the first codon of a messenger RNA (mRNA) transcript translated by a ribosome. Definition: first sentence of Wikipedia: Start codon (CC BY-SA 4.0)
- Stem-cell niche
- Stem-cell niche refers to a microenvironment, within the specific anatomic location where stem cells are found, which interacts with stem cells to regulate cell fate. Also: niches. Definition: first sentence of Wikipedia: Stem-cell niche (CC BY-SA 4.0)
- Stem-loop
- Stem-loops are nucleic acid secondary structural elements which form via intramolecular base pairing in single-stranded DNA or RNA. Definition: first sentence of Wikipedia: Stem-loop (CC BY-SA 4.0)
- Stereocilia
- Stereocilia (or stereovilli or villi) are non-motile apical cell modifications. Definition: first sentence of Wikipedia: Stereocilia (CC BY-SA 4.0)
- Steroid hormone receptor
- Steroid hormone receptors are found in the nucleus, cytosol, and also on the plasma membrane of target cells. Also: steroid hormone receptors. Definition: first sentence of Wikipedia: Steroid hormone receptor (CC BY-SA 4.0)
- Sterol
- A sterol is any organic compound with a skeleton closely related to cholestan-3-ol and having a hydroxyl group at carbon 3. Also: sterols. Definition: first sentence of Wikipedia: Sterol (CC BY-SA 4.0)
- Stinger
- A stinger (or sting) is a sharp organ found in various animals (typically insects and other arthropods) capable of injecting venom, usually by piercing the epidermis of another animal. Definition: first sentence of Wikipedia: Stinger (CC BY-SA 4.0)
- Stock (firearms)
- A gunstock or often simply stock, the back portion of which is also known as a shoulder stock, a buttstock, or simply a butt, is a part of a long gun that provides structural support, to which the barrel, action, and firing mechanism are attached. Also: telescoping stock. Definition: first sentence of Wikipedia: Stock (firearms) (CC BY-SA 4.0)
- Stomach
- The stomach is a muscular, hollow organ in the upper gastrointestinal tract of humans and many other animals, including several invertebrates. Definition: first sentence of Wikipedia: Stomach (CC BY-SA 4.0)
- Stop codon
- In molecular biology, a stop codon (or termination codon) is a codon (nucleotide triplet within messenger RNA) that signals the termination of the translation process of the current protein. Also: stop codons. Definition: first sentence of Wikipedia: Stop codon (CC BY-SA 4.0)
- Striated muscle tissue
- Striated muscle tissue is a muscle tissue that features repeating functional units called sarcomeres. Definition: first sentence of Wikipedia: Striated muscle tissue (CC BY-SA 4.0)
- Stroma (fluid)
- Stroma, in botany, refers to the colorless fluid surrounding the thylakoids (membrane-bound, sub-organelle compartments) within the chloroplast. Also: stroma, stromal. Definition: first sentence of Wikipedia: Stroma (fluid) (CC BY-SA 4.0)
- Submachine gun
- A submachine gun (SMG) or sub-gun is a magazine-fed automatic carbine designed to fire handgun cartridges. Definition: first sentence of Wikipedia: Submachine gun (CC BY-SA 4.0)
- Subsonic ammunition
- Subsonic ammunition is ammunition designed to operate at velocities below the speed of sound (Mach 1), which at standard conditions is 340.29 m/s. Also: subsonic. Definition: first sentence of Wikipedia: Subsonic ammunition (CC BY-SA 4.0)
- Subspecies
- A subspecies is a taxonomic rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (morphology), but that can successfully interbreed. Definition: first sentence of Wikipedia: Subspecies (CC BY-SA 4.0)
- Substance (chemistry)
- In chemistry, a substance is a unique form of matter with constant chemical composition and characteristic properties. Also: substance. Definition: first sentence of Wikipedia: Substance (chemistry) (CC BY-SA 4.0)
- Substituent
- In organic chemistry, a substituent is one or a group of atoms that replaces (one or more) atoms, thereby becoming a moiety in the resultant (new) molecule. Also: substituted. Definition: first sentence of Wikipedia: Substituent (CC BY-SA 4.0)
- Substrate (chemistry)
- In chemistry, the term substrate is highly context-dependent. Also: substrate, substrates. Definition: first sentence of Wikipedia: Substrate (chemistry) (CC BY-SA 4.0)
- Sugar
- Sugar is a class of sweet-tasting, soluble carbohydrates, many of which are used in food. Also: sugars. Definition: first sentence of Wikipedia: Sugar (CC BY-SA 4.0)
- Sulfur
- Sulfur, also spelled as sulphur, is a chemical element; it has symbol S and atomic number 16. Definition: first sentence of Wikipedia: Sulfur (CC BY-SA 4.0)
- Sunflower oil
- Sunflower oil is the non-volatile oil pressed from the seeds of the sunflower (Helianthus annuus). Also: sunflower seeds. Definition: first sentence of Wikipedia: Sunflower oil (CC BY-SA 4.0)
- Suspended animation
- Suspended animation is the slowing or stopping of biological function so that physiological capabilities are preserved. Definition: first sentence of Wikipedia: Suspended animation (CC BY-SA 4.0)
- Symbiosis
- Symbiosis is any close and long-term biological interaction between two organisms of different species. Also: symbiotic. Definition: first sentence of Wikipedia: Symbiosis (CC BY-SA 4.0)
- Sympathetic ganglia
- The sympathetic ganglia, or paravertebral ganglia, are autonomic ganglia of the sympathetic nervous system. Definition: first sentence of Wikipedia: Sympathetic ganglia (CC BY-SA 4.0)
- Symplast
- The symplast (from Greek sym "together" + plasma "formed or moulded substance") is the continuous, living network of cytoplasm that extends through most plant tissues. Also: symplastic. Definition: first sentence of Wikipedia: Symplast (CC BY-SA 4.0)
- Synapse
- In the nervous system, a synapse is a structure that allows a neuron to exchange (receive or send) signals with another cell in its immediate vicinity. Also: synapses. Definition: first sentence of Wikipedia: Synapse (CC BY-SA 4.0)
- Synaptic vesicle
- In a neuron, synaptic vesicles (or neurotransmitter vesicles) store various neurotransmitters that are released at the synapse. Also: synaptic vesicles. Definition: first sentence of Wikipedia: Synaptic vesicle (CC BY-SA 4.0)
- Synonym (taxonomy)
- In biological taxonomy, a synonym is one of two or more scientific names that apply to the same taxon. Also: junior synonym, synonym. Definition: first sentence of Wikipedia: Synonym (taxonomy) (CC BY-SA 4.0)
- Systems biology
- Systems biology is the computational and mathematical analysis and modeling of complex biological systems. Also: analysis. Definition: first sentence of Wikipedia: Systems biology (CC BY-SA 4.0)
T
- Taxonomy (biology)
- In biology, taxonomy is the scientific study of naming, defining (circumscribing) and classifying groups of biological organisms based on shared characteristics. Also: taxonomy. Definition: first sentence of Wikipedia: Taxonomy (biology) (CC BY-SA 4.0)
- Teleost
- Teleostei, members of which are known as teleosts, is, by far, the largest group of ray-finned fishes (class Actinopterygii), with 96% of all extant species of fish. Definition: first sentence of Wikipedia: Teleost (CC BY-SA 4.0)
- Telomerase
- Telomerase, also called terminal transferase, is a ribonucleoprotein that adds a species-dependent telomere repeat sequence to the 3' end of telomeres. Definition: first sentence of Wikipedia: Telomerase (CC BY-SA 4.0)
- Terpene
- Terpenes are a large and diverse class of natural products with the general formula, where n ≥ 2. Also: terpenes. Definition: first sentence of Wikipedia: Terpene (CC BY-SA 4.0)
- Terpenoid
- Terpenoids, also known as isoprenoids, are a class of naturally occurring organic chemicals derived from the 5-carbon compound isoprene and its derivatives called terpenes, diterpenes, etc. Also: isoprenoids. Definition: first sentence of Wikipedia: Terpenoid (CC BY-SA 4.0)
- Tetrose
- In organic chemistry, a tetrose is a monosaccharide with 4 carbon atoms. Definition: first sentence of Wikipedia: Tetrose (CC BY-SA 4.0)
- Thallophyte
- Thallophytes (Thallophyta or Thallobionta) are a polyphyletic group of non-motile organisms traditionally described as "thalloid plants", "relatively simple plants" or "lower plants". Also: thallophytes. Definition: first sentence of Wikipedia: Thallophyte (CC BY-SA 4.0)
- Thermal energy
- The term "thermal energy" is often used ambiguously in physics and engineering. Also: thermal kinetic energy. Definition: first sentence of Wikipedia: Thermal energy (CC BY-SA 4.0)
- Threonine
- Threonine (symbol Thr or T) is an amino acid that is used in the biosynthesis of proteins. Definition: first sentence of Wikipedia: Threonine (CC BY-SA 4.0)
- Thylakoid
- Thylakoids are membrane-bound compartments inside chloroplasts and cyanobacteria. Also: thylakoid membrane. Definition: first sentence of Wikipedia: Thylakoid (CC BY-SA 4.0)
- Thymine
- Thymine (symbol T or Thy) is one of the four nucleotide bases in the nucleic acid of DNA that are represented by the letters G–C–A–T. The others are adenine, guanine, and cytosine. Definition: first sentence of Wikipedia: Thymine (CC BY-SA 4.0)
- Thymus
- The thymus is a specialized primary lymphoid organ of the immune system. Definition: first sentence of Wikipedia: Thymus (CC BY-SA 4.0)
- Toll-like receptor
- Toll-like receptors (TLRs) are a class of proteins that play a key role in the innate immune system. Also: toll-like receptors. Definition: first sentence of Wikipedia: Toll-like receptor (CC BY-SA 4.0)
- Tonsil
- The tonsils are a set of lymphoid organs facing into the aerodigestive tract, which is known as Waldeyer's tonsillar ring and consists of the adenoid tonsil (or pharyngeal tonsil), two tubal tonsils, two palatine tonsils, and the lingual tonsils. Also: tonsils. Definition: first sentence of Wikipedia: Tonsil (CC BY-SA 4.0)
- Toxin
- A toxin is a naturally occurring poison produced by metabolic activities of living cells or organisms. Also: toxins. Definition: first sentence of Wikipedia: Toxin (CC BY-SA 4.0)
- Trail pheromone
- Trail pheromones are semiochemicals secreted from the body of an individual to affect the behavior of another individual receiving it. Also: trail pheromones. Definition: first sentence of Wikipedia: Trail pheromone (CC BY-SA 4.0)
- Transcortin
- Transcortin, also known as corticosteroid-binding globulin (CBG) or serpin A6, is a protein produced in the liver in animals. Also: corticosteroid-binding globulin. Definition: first sentence of Wikipedia: Transcortin (CC BY-SA 4.0)
- Transcription factor
- In molecular biology, a transcription factor (TF) (or sequence-specific DNA-binding factor) is a protein that controls the rate of transcription of genetic information from DNA to messenger RNA, by binding to DNA sequences. Also: transcription factors. Definition: first sentence of Wikipedia: Transcription factor (CC BY-SA 4.0)
- Transesterification
- Transesterification is the process of exchanging the organic functional group R″ of an ester with the organic group R' of an alcohol. Definition: first sentence of Wikipedia: Transesterification (CC BY-SA 4.0)
- Translocase
- Translocase is a general term for a protein that assists in moving another molecule, usually across a cell membrane. Definition: first sentence of Wikipedia: Translocase (CC BY-SA 4.0)
- Translocon
- The translocon (also called a translocator or translocation channel) is a general term for a protein channel in biological membranes that functions to move polypeptides across the membrane or insert them into the lipid bilayer. Definition: first sentence of Wikipedia: Translocon (CC BY-SA 4.0)
- Transmembrane protein
- A transmembrane protein is a type of integral membrane protein that spans the entirety of the cell membrane. Also: transmembrane, transmembrane proteins. Definition: first sentence of Wikipedia: Transmembrane protein (CC BY-SA 4.0)
- Transposable element
- Transposable elements (TEs), also known as transposons, jumping genes, or mobile genetic elements, are DNA sequences that can change their position, or translocate, within a genome. Also: transposons. Definition: first sentence of Wikipedia: Transposable element (CC BY-SA 4.0)
- Trawling
- Trawling is an industrial method of fishing that involves pulling a fishing net through the water behind one or more boats. Also: trawl. Definition: first sentence of Wikipedia: Trawling (CC BY-SA 4.0)
- Trichocyst
- A trichocyst is an organelle found in certain ciliates and dinoflagellates. Definition: first sentence of Wikipedia: Trichocyst (CC BY-SA 4.0)
- Triglyceride
- A triglyceride (from tri- and glyceride; also TG, triacylglycerol, TAG, or triacylglyceride) is an ester derived from glycerol and three fatty acids. Also: triglycerides. Definition: first sentence of Wikipedia: Triglyceride (CC BY-SA 4.0)
- Triose
- A triose is a monosaccharide, or simple sugar, containing three carbon atoms. Definition: first sentence of Wikipedia: Triose (CC BY-SA 4.0)
- Triterpene
- Triterpenes are a class of terpenes composed of six isoprene units with the molecular formula C30H48; they may also be thought of as consisting of three terpene units. Definition: first sentence of Wikipedia: Triterpene (CC BY-SA 4.0)
- Tropomyosin
- Tropomyosin is a two-stranded alpha-helical, coiled coil protein found in many animal and fungal cells. Definition: first sentence of Wikipedia: Tropomyosin (CC BY-SA 4.0)
- Tryptophan
- Tryptophan (symbol Trp or W), historically also known as tryptophane, is an α-amino acid that is used in the biosynthesis of proteins. Definition: first sentence of Wikipedia: Tryptophan (CC BY-SA 4.0)
- Tubulin
- Tubulin in molecular biology can refer either to the tubulin protein superfamily of globular proteins, or one of the member proteins of that superfamily. α- and β-tubulins polymerize into microtubules, a major component of the eukaryotic cytoskeleton. Definition: first sentence of Wikipedia: Tubulin (CC BY-SA 4.0)
- Turgor pressure
- Turgor pressure is the force within the cell that pushes the plasma membrane against the cell wall. Also: turgor. Definition: first sentence of Wikipedia: Turgor pressure (CC BY-SA 4.0)
- Two-pore-domain potassium channel
- The two-pore-domain or tandem pore domain potassium channels are a family of 15 members that form what is known as leak channels which possess Goldman-Hodgkin-Katz (open) rectification. Also: potassium leak channels. Definition: first sentence of Wikipedia: Two-pore-domain potassium channel (CC BY-SA 4.0)
- Type (biology)
- In biology, a type is a particular specimen (or in some cases a group of specimens) of an organism to which the scientific name of that organism is formally associated. Also: type specimen. Definition: first sentence of Wikipedia: Type (biology) (CC BY-SA 4.0)
- Tyrosine
- L-Tyrosine or tyrosine (symbol Tyr or Y) or 4-hydroxyphenylalanine is one of the 20 standard amino acids that are used by cells to synthesize proteins. Definition: first sentence of Wikipedia: Tyrosine (CC BY-SA 4.0)
U
- Ubiquitin
- Ubiquitin is a small (8.6) regulatory protein found in most tissues of eukaryotic organisms, i.e., it is found ubiquitously. Definition: first sentence of Wikipedia: Ubiquitin (CC BY-SA 4.0)
- Ubiquitin ligase
- A ubiquitin ligase (also called an E3 ubiquitin ligase) is a protein that recruits an E2 ubiquitin-conjugating enzyme that has been loaded with ubiquitin, recognizes a protein substrate, and assists or directly catalyzes the transfer of ubiquitin from the E2 to the protein substrate. Also: ubiquitin ligases. Definition: first sentence of Wikipedia: Ubiquitin ligase (CC BY-SA 4.0)
- Ultrastructure
- Ultrastructure (or ultra-structure) is the architecture of cells and biomaterials that is visible at higher magnifications than found on a standard optical light microscope. Definition: first sentence of Wikipedia: Ultrastructure (CC BY-SA 4.0)
- Unicellular organism
- A unicellular organism, also known as a single-celled organism, is an organism that consists of a single cell, unlike a multicellular organism that consists of multiple cells. Also: unicellular. Definition: first sentence of Wikipedia: Unicellular organism (CC BY-SA 4.0)
- Upstream and downstream (DNA)
- In molecular biology and genetics, upstream and downstream both refer to relative positions of genetic code in DNA or RNA. Also: upstream. Definition: first sentence of Wikipedia: Upstream and downstream (DNA) (CC BY-SA 4.0)
- Uracil
- Uracil (symbol U or Ura) is one of the four nucleobases in the nucleic acid RNA. Definition: first sentence of Wikipedia: Uracil (CC BY-SA 4.0)
- Urate oxidase
- In molecular biology, urate oxidase (UO), also known as uricase or factor-independent urate hydroxylase, is a metabolic enzyme found in nearly all species from bacteria to mammals, but is not expressed in humans, great apes, and certain New World monkeys, in which it exists as a pseudogene. Also: uric acid oxidase. Definition: first sentence of Wikipedia: Urate oxidase (CC BY-SA 4.0)
- Uterine cancer
- Uterine cancer, also known as womb cancer, includes two types of cancer that develop from the tissues of the uterus. Also: uterine. Definition: first sentence of Wikipedia: Uterine cancer (CC BY-SA 4.0)
V
- Valine
- Valine (symbol Val or V) is an α-amino acid that is used in the biosynthesis of proteins. Definition: first sentence of Wikipedia: Valine (CC BY-SA 4.0)
- Vector (molecular biology)
- In molecular cloning, a vector is any particle (e.g., plasmids, cosmids, Lambda phages) used as a vehicle to artificially carry a foreign nucleic sequence – usually DNA – into another cell, where it can be replicated and/or expressed. Also: vectors. Definition: first sentence of Wikipedia: Vector (molecular biology) (CC BY-SA 4.0)
- Venom
- Venom or zootoxin is a type of toxin produced by an animal that is actively delivered to other animals through a wound by means of a bite, sting or similar penetrative action, usually via a specially evolved venom apparatus, such as fangs or a stinger, in a process called envenomation. Definition: first sentence of Wikipedia: Venom (CC BY-SA 4.0)
- Vertebrate
- Vertebrates, also called craniates, are animals with a vertebral column and a cranium. Also: vertebrates. Definition: first sentence of Wikipedia: Vertebrate (CC BY-SA 4.0)
- Vesicle (biology and chemistry)
- In cell biology, a vesicle is an organelle within or outside a cell, consisting of liquid or cytoplasm enclosed by a lipid bilayer. Also: vesicle, vesicles. Definition: first sentence of Wikipedia: Vesicle (biology and chemistry) (CC BY-SA 4.0)
- Viroid
- Viroids are small single-stranded, circular RNAs that are infectious pathogens. Also: viroids. Definition: first sentence of Wikipedia: Viroid (CC BY-SA 4.0)
- Virology
- Virology is the scientific study of biological viruses. Definition: first sentence of Wikipedia: Virology (CC BY-SA 4.0)
- Virulence
- Virulence is a pathogen's or microorganism's ability to cause damage to a host. Definition: first sentence of Wikipedia: Virulence (CC BY-SA 4.0)
- Virulence factor
- Virulence factors (preferably known as pathogenicity factors or effectors in botany) are cellular structures, molecules and regulatory systems that enable microbial pathogens (bacteria, viruses, fungi, and protozoa) to achieve the following: Also: virulence factors. Definition: first sentence of Wikipedia: Virulence factor (CC BY-SA 4.0)
- Virus
- A virus is a submicroscopic infectious agent that replicates only inside the living cells of an organism. Also: viruses. Definition: first sentence of Wikipedia: Virus (CC BY-SA 4.0)
- Viscoelasticity
- Viscoelasticity is a material property that combines both viscous and elastic characteristics. Also: viscous. Definition: first sentence of Wikipedia: Viscoelasticity (CC BY-SA 4.0)
- Visual phototransduction
- Visual phototransduction is the sensory transduction process of the visual system by which light is detected by photoreceptor cells (rods and cones) in the vertebrate retina. Definition: first sentence of Wikipedia: Visual phototransduction (CC BY-SA 4.0)
- Vitamin
- Vitamins are organic molecules (or a set of closely related molecules called vitamers) that are essential to an organism in small quantities for proper metabolic function. Also: fat-soluble vitamins. Definition: first sentence of Wikipedia: Vitamin (CC BY-SA 4.0)
- Viviparity
- In animals, viviparity is the development of the embryo inside the body of the mother, with the maternal circulation providing for the metabolic needs of the embryo's development, until the mother gives birth to a fully or partially developed juvenile that is at least metabolically independent. Also: viviparous. Definition: first sentence of Wikipedia: Viviparity (CC BY-SA 4.0)
- Voltage-gated ion channel
- Voltage-gated ion channels are a class of transmembrane proteins that form ion channels that are activated by changes in a cell's electrical membrane potential near the channel. Also: voltage-gated ion channels. Definition: first sentence of Wikipedia: Voltage-gated ion channel (CC BY-SA 4.0)
W
- Waivers (NHL)
- Waivers are a National Hockey League (NHL) labour management procedure that requires an NHL team, under specific circumstances, to make a professional ice hockey player's contract and rights available for all other NHL teams to claim. Also: waivers. Definition: first sentence of Wikipedia: Waivers (NHL) (CC BY-SA 4.0)
- Walnut
- A walnut is the edible seed of any tree of the genus Juglans (family Juglandaceae), particularly the Persian or English walnut, Juglans regia. Also: walnuts. Definition: first sentence of Wikipedia: Walnut (CC BY-SA 4.0)
- Wax
- Waxes are a diverse class of organic compounds that are lipophilic solids that are malleable near ambient temperatures. Also: waxes. Definition: first sentence of Wikipedia: Wax (CC BY-SA 4.0)
- Work (physics)
- In science, work is the energy transferred to or from an object via the application of force along a displacement. Also: energy. Definition: first sentence of Wikipedia: Work (physics) (CC BY-SA 4.0)
Y
- Yeast
- A yeast is any species of fungus that grows primarily in a unicellular form and reproduces via budding or fission. Definition: first sentence of Wikipedia: Yeast (CC BY-SA 4.0)
- Yolk sac
- The yolk sac is a membranous sac attached to an embryo, formed by cells of the hypoblast layer of the bilaminar embryonic disc. Definition: first sentence of Wikipedia: Yolk sac (CC BY-SA 4.0)
Z
- Zygote
- A zygote is a eukaryotic cell formed by a fertilization event between two gametes. Definition: first sentence of Wikipedia: Zygote (CC BY-SA 4.0)
Α
- Α-Linolenic acid
- α-Linolenic acid, also known as alpha-linolenic acid (ALA) (from Greek alpha denoting "first" and linon meaning flax), is an n−3, or omega-3, essential fatty acid. Also: alpha-linolenic acid. Definition: first sentence of Wikipedia: Α-Linolenic acid (CC BY-SA 4.0)